Nothing says an NFL player is unhappy with his contract like a training camp holdout. This summer's missing campers? Rams defensive tackle Aaron Donald, Steelers running back Le'Veon Bell, Texans left tackle Duane Brown and Raiders left tackle Donald Penn.

Being involved in two lengthy holdouts during my agent days with Jimmy Smith and Keenan McCardell gives me some insight into these types of contract disputes. Smith's 38-day holdout in 2002 ended with him getting a new contract from the Jaguars at the end of the preseason. McCardell's dispute with the Buccaneers in 2004 lasted 82 days before he was dealt to the Chargers right before the trading deadline.

The cost of a holdout

Donald, Brown and Penn can be fined a maximum of $40,000 for each day of training camp missed because they are under contract. Penn is subject to an additional fine of one week's base salary for each preseason game missed (1/17 of $5.85 million or approximately $345,000) because he signed his contract as an unrestricted free agent. Donald is still under his rookie contract. Brown's deal is a contract extension.

A year of service toward free agency isn't earned when a player under contract doesn't report to his team at least 30 days before NFL's first regular season game. This year's deadline is Aug. 8. The date is somewhat relevant only to Donald because he is entering his fourth NFL season. If he plays out his rookie contract, which includes a fifth-year option in 2018, he would still have enough service time to become an unrestricted free agent, provided he doesn't miss the deadline both this year and next.

A team can also recover a portion of a player's signing bonus. A total of 15 percent of the prorated amount of signing bonus can be recouped on the sixth day of a training camp holdout. It's one percent for each additional missed day with a maximum of 25 percent of the prorated amount during training camp. An additional 25 percent can be recovered with the first missed regular season game. After four missed weeks, a team can recover 1/17 of the prorated amount for each additional week of the player's absence. The maximum a team can recover in a season is the entire prorated amount of the player's signing bonus in that contract year.

Donald is the only holdout that has to worry about signing bonus recoupment. The Rams right to recover $213,450 of Donald's $5.692 million signing bonus (15 percent of the $1.423 million prorated amount) was triggered on August 3. None of the $12.5 million signing bonus that Brown received in his 2012 extension can be recovered because proration of the bonus ended in 2016. Penn's deal doesn't contain a signing bonus.

The financial penalties don't apply to unsigned draft picks, as well as players with restricted free agent, franchise or transition tenders who aren't under contract that miss training camp. Their attendance isn't required because of the absence of a signed contract. Bell falls into this category because he's a franchise player who remains unsigned. Players under contract are withholding services they are contractually obligated to perform while Bell has no such obligation.

Who blinks first?

A holdout is ultimately a test of each side's resolve. Once a player misses the beginning of training camp, there usually isn't much dialogue between a player's agent and the team early on when there is a contract impasse. Teams typically approach a holdout as if the player is injured. They look for replacements at his position either internally or from available free agents and evaluate how the team performs with him absent.

Most holdouts don't mind missing the daily grind of training camp, but as the regular season gets closer, a player may start having second thoughts about his decision. If meaningful dialogue on a new contract resumes, it may not be until the middle of the preseason. There were hardly any conversations with the Buccaneers during most of McCardell's holdout because both sides were firmly entrenched in their positions.

Savvy teams will refrain from talking to the media about the player besides an obligatory statement about being unwilling to publicly comment on a player who isn't in training camp or that the player's contributions are valued and welcome him returning to the team when he is ready to honor his contract. In most cases, fans don't take a player's side in a contract dispute with a team. The public has a difficulty relating to a player being unhappy with what is a lucrative contract in their eyes or rejecting a substantial offer. Unusual circumstances are required for public sentiment to be with the player.

A major obstacle a player must overcome is a team's concern about establishing a precedent of giving into a player's demands for a new contract through a holdout. Although teams should be able to easily make distinctions based on each player's particular circumstances, they don't want to send a signal to the other team members that they could get rewarded by holding the team hostage. This is especially the case when there is a new owner, or new general manager or a new head coach with a hands-off owner. Along those lines, some teams have a philosophy that they won't have meaningful dialogue about a new contract while the player is a holdout.

Prominent players at impact positions have the best chance of success, provided they remain patient and give the impression that they are willing to continue their absence into the regular season. Once a player decides to end an unsuccessful holdout, some teams will reduce the fines accumulated as a gesture of goodwill, especially with a player who is one of the most important players on the team or a veteran that commands a lot of respect among his teammates.

The longer a holdout drags on, the more of a distraction it can become with coaches and teammates being constantly asked about it by the media before and after games and practices. It also helps to be on playoff contenders/teams with Super Bowl aspirations or teams where the head coach or general manager is on the hot seat. Pressure may be put on ownership to do whatever it takes to get the player back into the fold as the regular season approaches. Smith's holdout was aided by Jacksonville's first-team offense struggling to move the football without him (16 punts in 17 offensive possessions).

Here's a look at each holdout's situation.

First-round picks selected under the rookie wage scale implemented by the 2011 collective bargaining agreement (CBA), like Donald, typically don't get new contracts after three seasons. Thirteen first-round picks have gotten extensions at this juncture of their NFL tenure over the last three years.

Fortunately for Donald, the Rams have a track record for rewarding first-round picks early. Wide receiver Tavon Austin and defensive end Robert Quinn received new deals no later than the middle of September of their fourth season.

The ongoing negotiations between Donald and the Rams should have produced an agreement by now, given the team's treatment of Austin. The Rams inexplicably gave Austin a four-year extension averaging approximately $10.5 million per year with $28.5 million of guarantees late last preseason despite underachieving in his first three NFL seasons. The 2013 eighth overall pick barely topped the 500-receiving yard mark for the first time during his career in 2016. Austin's contract also contains $14 million of incentives and base salary escalators in which he could realistically make a minimum of $1 million annually under these clauses by performing like a good wide receiver.

Donald, the 2014 Defensive Rookie of the Year, has quickly become the NFL's most disruptive force from the interior of a defensive line. According to Pro Football Focus (PFF), Donald's 82 quarterback pressures (combined sacks, quarterback hurries and quarterback hits) were the third-most in the league last season and led NFL interior defensive lineman. Donald took the top spot in PFF's top 101 players for the 2015 season. He was second in PFF's 2016 rankings. Donald has also been a consensus first-team All-Pro the past two seasons.

Aaron Donald's play suggests he deserves to be paid more than Ndamukong Suh.  USATSI

The Rams possess leverage over Donald because he is under contract this season for approximately $1.8 million and for $6.892 million in 2018 since the Rams picked up their fifth-year option with him. Donald could also be designated a franchise player in 2019 and 2020.

Teams giving highly-accomplished first-round picks extremely early extensions haven't exploited their leverage. Cowboys center Travis Frederick, Panthers inside linebacker Luke Kuechly, Cardinals cornerback Patrick Peterson and Texans defensive end J.J. Watt became the highest-paid player (by average year salary) at their respective positions. Each player received All-Pro honors in two of their first three years, just like Donald.

Based on their treatment, the Rams should at least be willing to make Donald the NFL's highest-paid interior defensive lineman over Ndamukong Suh. Suh signed a six-year, $114.375 million contract with the Dolphins in 2015, which averages $19,062,500 and contains nearly $60 million fully guaranteed. Donald insisting upon being the NFL's first $20 million per-year non-quarterback with more than the $70 million in guarantees Von Miller received from the Broncos in 2016 would be justified. Miller became the league's highest paid non-quarterback at $19,083,333 per year with his extension. The Cowboys making Zack Martin, who has earned All-Pro honors in his each of three NFL seasons, the NFL's highest-paid offensive guard before Donald gets a new deal would likely added to his resolve.

Bell would have easily topped a declining running back market if he had accepted the five-year deal the Steelers offered. Instead, he will play the 2017 season on a one-year contract, presumably for his $12.12 million franchise tag. According to NFL Media's Tom Pelissero, Bell rejected a five-year deal averaging more than $12 million per year where $30 million was in the first two years and $42 million was over three years.

Bell is following in the footsteps of other unsigned franchise players in recent years by minimizing the risk of a serious injury with his training camp absence. Chiefs safety Eric Berry didn't sign his franchise tender last year until 13 days before Kansas City's first regular-season game. Bills safety Jairus Byrd missed 25 days of training camp in 2013 before accepting his franchise tag.

Bell is allowed to negotiate his one-year salary with the Steelers and other conditions relating to his franchise player status. He could insist on a clause that would prohibit the Steelers from using a franchise or transition designation on him in 2018, also known as a prohibition clause, in order to sign his tender and report.

Obtaining a prohibition clause might be difficult for Bell. A franchise player hasn't gotten this type of provision since 2008 when the Titans gave Albert Haynesworth a conditional prohibition clause. It was triggered by Haynesworth making the Pro Bowl, having at least 60 percent defensive playtime, or 53 percent defensive playtime and the Titans winning at least 10 games or ranking in the top five in total defense.

Le'Veon Bell won't likely sign his franchise tender until late in the preseason.  USATSI

Linebacker Lance Briggs and cornerback Asante Samuel had clauses similar to Haynesworth's when they were franchised in 2007 by the Bears and Patriots respectively. Samuel's prohibition clause was triggered by him having at least 60 percent playtime on defense or the Patriots winning at least 12 games. Briggs' clause was predicated on him having at least 75 percent playtime on defense. Jeff Backus and Nate Clements received the last unconditional prohibition clauses in 2006 with the Lions and Bills respectively.

Bell missing any part of the regular season would seem remote with him losing almost $715,000 of salary for each week missed. It hasn't happened with a healthy franchise player since the 2006 CBA implemented the July multi-year deal deadline. This excludes Jason Pierre-Paul, who missed eight regular season games in 2015 while he wasn't cleared physically by the Giants from his Fourth of July fireworks accident. Dunta Robinson came closest when he signed his franchise tender four days before the Texans' 2009 regular-season opener.

Brown has two years left on the six-year, $53.4 million extension he signed in 2012. Skipping offseason workouts triggered a $250,000 base salary de-escalator to reduce Brown's 2017 income from $9.65 million to $9.4 million. Although the Texans gave J.J. Watt a new deal in 2014 with two years remaining and renegotiated Andre Johnson's contract in 2010 with five years to go, redoing contracts before a contract year is an uncommon team occurrence.

Houston's top contract priority is getting wide receiver DeAndre Hopkins, who is in his contract year, signed long-term. Addressing Brown's contract this preseason would potentially cause the Texans headaches in the future. Outside linebacker Whitney Mercilus is outperforming his four-year, $26 million extension that runs through the 2019 season. He would likely expect the Texans to do the same with his contract next season when he has two years left if Brown gets a new deal.

It might be inevitable for the Texans to treat Watt like Johnson, provided he returns to his previous form after two back surgeries last year. Watt once again becoming the closest thing to a modern day Reggie White would be a tremendous bargain considering he is currently under contract for four additional seasons after this one for $57 million over those years.

Paying teammate Jadeveon Clowney, the first overall pick in the 2014 NFL Draft, more than Watt next year when he is in his contract year will likely be problematic if the three-time NFL Defensive Player of the Year continues to be a dominant force. The Texans would need to adjust or renegotiate Watt's contract sooner rather than later as well after doing so for the lesser-accomplished Brown to avoid having a disgruntled cornerstone of the franchise.

The deck is stacked against Brown getting a new deal even though offensive tackle is a more glaring weakness without him. In addition to Houston's reluctance to rework contracts with multiple years remaining, there is a team policy against in-season contract negotiations.

Penn's mistake was signing a two-year, $12.5 million contract (worth up to $14 million with incentives) in 2016 instead of a one-year deal. There aren't any guarantees or security in the second year. The Raiders didn't get a salary cap break with the second year because Penn's deal is structured like nearly all of the team's other veteran contracts. Penn's salary cap number and cash are the same in each year because his deal doesn't have a signing bonus.

Penn might have been a highly sought-after free agent despite being 34 years old after a 2016 season in which he only gave up one sack and was named to the Pro Bowl. Age didn't prevent 35-year-old Andrew Whitworth from signing a three-year, $33.75 million deal (worth a maximum of $36 million through incentives) with the Rams in free agency.

Raiders general manager Reggie McKenzie seems receptive to working on a new deal for Penn provided he ends his holdout. The additional fine of a week's base salary (just under $345,000) for every missed preseason game, starting Aug. 12, could be the impetus for Penn to return. A two-year extension in the $10 million per year neighborhood shouldn't be out of the question for Penn considering the Eagles recently re-did Jason Peters' deal so he is under contract through the 2019 season for $27.25 million. Peters is 35. The Peters deal can be worth as much as $30.25 million because of incentives and base salary escalators.