Julius Thomas is 26 years old, he's one of the NFL's most productive tight ends and he's a free agent this offseason. According to his agent, Frank Bauer, Thomas wants to remain with the Denver Broncos, but the two sides were unable to work out an agreeable deal.

"The Broncos came to me, we tried to get it done, it didn't work," Bauer said, according to The Denver Post. "Does Julius love Denver? Yes. Does Julius love the fans there? No question. Does he love the organization and the community? Look at what he does for kids in that town. But for some reason people are trying to tear him down. In my opinion, what they're doing by tearing him down is pushing him away."

Now, it's not exactly clear who or what Bauer is referring to when he says that people are trying to tear Julius down. I can't recall seeing many (if any) leaks from the Denver camp about how Thomas is a product of Peyton Manning's excellence and the attention drawn by Demaryius Thomas, for example. It's of course possible those kinds of things were said in private conversations behind closed doors and not released for public consumption, though, and that could be rubbing the Thomas camp the wrong way. Either way, Bauer did give a clear answer indicating exactly why the contract discussions were not fruitful.

"The main thing was the structure," Bauer said. "In any contract in the National Football League, it all has to do with how the guarantees are written. Are there full skill/injury/cap guarantees? Or are they conditional? There are clubs that do it the old way. And they're getting their players done and keeping their own. In this case, the guarantees were too low. The guarantees were conditional."

Thomas played in 13 games last season, missing three with an injured ankle and playing hurt in a few others, and he also missed two games due to injury in 2013. After being drafted by Denver in 2011, he missed his entire rookie season due to injury and played only five games in his second year in the league, so it is somewhat understandable that any contract offer may not be fully guaranteed for injury. After all, he's played only 32 of a possible 64 regular games in his four-year career. Thomas has been wildly productive (and mostly healthy) the last two seasons, though, so it's also understandable that he and his agent want a deal that reflects his prodigious talent and contributions.

There's an additional issue to be considered, though.

Denver currently has just south of $27 million in cap space this offseason, according to Spotrac, which tracks the salary figures of every team and player in the league. A bunch of that space will likely be eaten up by a new contract for Demaryius, who is seemingly a higher priority for Denver than Julius. The Broncos also have Terrance Knighton, Rahim Moore, Orlando Franklin and Brandon Marshall looking for new deals, and they're all players of varying import to Denver's success. With only $26 million to work with right now, this could be why they're finding it difficult to come to an agreement with Julius.

The Broncos can create more cap space by converting the base salaries of certain players into a signing bonus and pushing the guaranteed money further into the future, but they only really have four players with sizable enough salaries for that type of move to make a difference: DeMarcus Ware, Von Miller, Ryan Clady and Peyton Manning are the only players on the roster with base salaries in excess of $5.5 million in 2015.

However, 2015 is the final year of Miller's current contract and both Ware and Manning's deals end in 2016. That leaves Denver not all that much room to push the money forward. It's been floated that they could restructure Peyton's contract to give them a little more breathing room, and that might make the most sense, but it could also prove costly in the future. Here's what former NFL agent Joel Corry wrote on that topic a few days back:

Restructuring Manning's contract could accomplish the same thing from a cap standpoint as a pay cut. Manning should be amendable to restructuring his contract, considering he did it twice while with the Colts. The problem is the Broncos haven't done any simple contract restructures for cap purposes during Manning's three years with the team. Denver can create $9.015 million in 2015 cap space if Manning's entire 2015 salary, except for his $970,000 league minimum, is converted into signing bonus. Manning's 2015 cap number would drop to $12.485 million but his 2016 cap number would balloon to $30.515 million. Up to three voidable years (2017 through 2019 contract years) could also be added to help with the bonus proration and create additional cap room. A maximum of $14.424 million in cap space can be freed up with this approach.

A more reasonable alternative could be a restructure creating the same $5 million of cap room the Denver Post's Mark Kiszla suggested with Manning cutting his 2015 salary from $19 million to $14 million. Under this scenario, Manning would still make $19 million but $10 million of his base salary would be converted to signing bonus to lower his cap number to $16.5 million. His 2016 cap number would become $26.5 million.

That's a lot of complicated maneuvering, and letting Manning's cap number balloon to $30ish million for 2016 when they'll have to dole out new contracts for Miller, Danny Trevathan, C.J. Anderson and others may not be the wisest fiscal policy. This is a tough balancing act that Denver is trying to pull off here, and what's best for the team may not perfectly align with what's best for one of their top free agents.

If the two sides can't come to an agreement, Thomas should be one of the most sought-after free agents on the market this offseason. There are currently 16 teams with at least $20 million in cap space, eight of whom have $30 million or more, and there will be more teams adding additional space as they restructure deals and cut unproductive players. It's a fairly deep tight end class in free agency, though, with players like Jordan Cameron, Charles Clay, Jermaine Gresham, Owen Daniels and Niles Paul also on the market. None of those players is nearly as big a talent as Thomas, but tight end hasn't exactly been a position where teams shell out a ton of money for free agents in the past, so cheaper options might prove attractive in the marketplace.

Talks between Julius Thomas and the Broncos have apparently broken down. (Getty Images)