Last year ended with a strong reminder for the Chargers.

It can't just be all about Melvin Ingram and Joey Bosa up front. 

After a 12-4 record and a rather effortless road playoff win in Baltimore, Los Angeles' season came to a screeching halt in New England against the Patriots in the divisional round. 

Tom Brady dropped back to pass 46 times in that game, and the Chargers failed to record a sack. Their pass rush registered just two quarterback hits all afternoon, and Brady completed 77.2 percent of his passes (for 346 yards), the highest completion percentage he's managed in a playoff game since the January 2007. My goodness. 

As a team, in the regular season, the Chargers finished 19th in defensive pressure rate. They pressured the opposing quarterback on 33.2 percent of drop backs faced, just below the league average of 33.7 percent. And for a team with reasonable Super Bowl aspirations, that's probably not good enough.

And I'm not going to fault the team's best players -- Ingram and Bosa -- for the team's relatively pedestrian performance getting after the quarterback.

On the interior, the top four defensive tackles in snaps played -- Darius Philon, Damion Square, Brandon Mebane, and Justin Jones -- combined for just 8.5 sacks. Bosa and Ingram combined for 12.5. 

And Philon, who had four quarterback takedowns of his own, signed with the Cardinals in free agency. Clearly, the Chargers needed to address the defensive tackle position in the draft and did so by selecting Notre Dame's Jerry Tillery at No. 28 overall.

As the CBS Sports' summer series examining training camp position battles rolls along, let's analyze the main candidates at the position, and predict who'll win the full-time jobs at the defensive tackle spot rotation during the Chargers' 2019 season.

The Veterans

Damion Square

The 6-2, 293-pound Square is your classic Alabama defensive lineman. He really flashes against the run and has mediocre-at-best pass-rushing ability. After coming into the league as an undrafted free agent in 2013, Square has carved out a role as serviceable depth inside for the Chargers. 

As a 29-year-old last year, he nearly doubled his career-high in snaps with 602 and had an admirable albeit unspectacular season. Square's most valuable attribute is his versatility. His best game came against the Browns in Week 6, when he predominantly aligned at end. 

Later in the year, he manned the underappreciated nose tackle spot and ate blockers. Square does his best work laterally. He's effective dispatching blocks, then scraping down the line in either direction to get his hands on the ball carrier. At times, his power helps him as a pass rusher, but Square lacks the initial burst or closing speed to routinely threaten offensive linemen en route to the quarterback. 

He turned 30 in February, but is fresh off his best NFL season relative to his high volume of snaps. With the youthful and springy Philon gone, Square should begin the year as one of the starters on the inside who'll, as usual, play end in some instances. And because of his good standing with the team and well-rounded game, I expect him to be one of the top two defensive tackles in snaps played this upcoming season. 

Brandon Mebane 

Defensive coordinator Gus Bradley knows Mebane well from their time together in Seattle from 2009 to 2012. Even then, Mebane had the easily overlooked but important role as the two-gapping nose tackle. That's when Mebane was still in his 20s. Now he's 34 and for as polished as his game has become executing his specific role, he provides minimal-at-most production as a pass rusher. 

In 2018, Mebane played 39 percent of the defensive snaps and frequently came off the field on second-and-long situations and third downs. 

It'd be foolish to expect anything more from him in his 13th season. In obvious run situations, Mebane can still be an asset to the Chargers. But as the NFL continues its pass-obsessed trend, his value will continue to decrease. With more dead money if cut than savings, Mebane is essentially a lock to make the roster but is bound to serve a very minimal, super-niche purpose that will provide a minor impact on the Chargers' defense on the plays that matter most -- passes.

Justin Jones

A member of the famed NC State line that featured Bradley Chubb, Kentavious Street and B.J. Hill -- all picked in the first four rounds -- Jones enjoyed a steady career with the Wolfpack with 22.5 tackles for loss and 9.5 sacks in three seasons. 

He was my No. 168 overall player in the 2018 draft class, and Los Angeles snagged him at No. 84 overall -- in the third round -- so to me, the Chargers didn't get the best value with his selection.

As is the case with most recent NC State defensive linemen, Jones was "NFL ready" in the strength department and it showed during his time in the ACC. Beyond the pop in his pads, nothing else really stood out about his game as a prospect, and as a rookie in Los Angeles, Jones had a rather inauspicious beginning to his pro career. 

He appeared on 364 snaps -- just 28.8 percent -- on defense and registered a half sack to go along with 17 total tackles. At 6-2 and 309 pounds with average-at-best athleticism, Jones is a defensive tackle only and, like Square, is sturdier against the run than he is dynamic as a pass rusher. 

He stated he took a professional approach this offseason, changing his diet and exercising in different ways to keep himself in shape without being on the football field. While a positive tweak, it's not unusual for second-year pros to embrace a more structured, rigorous offseason philosophy after feeling the shock of how difficult the NFL is as rookies. 

Jones should see an uptick in snaps during the regular season, but likely needs a noticeably impactful training camp and preseason -- especially in passing situations -- to earn one of the starting gigs at defensive tackle. 

The Rookies

Jerry Tillery

Tillery started the pre-draft process as a late first-round prospect on my board based on everything we saw from him on film at Notre Dame. Tillery has length, motor, and an array of pass-rushing moves. He had eight sacks, 9.5 tackles for loss, and per Pro Football Focus, recorded a whopping 48 quarterback pressures last season, the third-most among all interior defensive linemen in college football. 

I wasn't expecting a big combine from the tall defensive tackle. Then he had a strong workout at nearly 6-foot-7 and 296 pounds. 

As an evaluator who places a sizable emphasis on athleticism, I vaulted Tillery all the way to No. 7 spot on my final big board after his combine performance. He ended the draft process as my No. 3 defensive tackle behind Ed Oliver and Quinnen Williams. So, yeah, the Chargers got Tillery at tremendous value. 

He's going to literally and figuratively stand out on the interior of Los Angeles' defensive line at north of 6-6. And he's going to be disruptive. During the winter and spring months, I repeatedly wrote about Tillery's "heavy" hands, which means when he strikes during his pass rush, his arms move blockers. Some defensive linemen who are karate masters with their hands don't have power behind them, so their pass-rushing moves are ineffective. 

Behind his hand use, Tillery's a high-energy player with plus athletic gifts. While he did have some stretches without traditional production last season, he consistently beat offensive linemen at the point of attack against the run and on pass plays. He has the complete game to be an instant impact rookie for the Chargers. I'll be surprised if Tillery doesn't finish the 2019 season with the most or second-most defensive snaps at the defensive tackle spot in Los Angeles. And he can certainly kick outside to end in base looks too thanks to his size, length, and athletic gifts. He's my pick to start next to Square in Week 1. 

Cortez Broughton 

As a draft guy, I was psyched when Broughton got picked, even if it was in the seventh round. From the moment I finished watching his film and grading him, the Cincinnati product was a clear draft sleeper of mine. He didn't earn a combine invite, but after Broughton's pro day, he was cemented inside my Top 100: 

Broughton finished as my No. 96 overall prospect in the 2019 class and the No. 10 defensive tackle. After spending years playing on the edge at 6-2 and around 290 pounds, he was finally moved inside as a senior. 

Before his final campaign with the Bearcats, Broughton had 10.5 tackles for loss and 3.5 sacks over three seasons. In 2018, given the freedom to simply attack up the field from a defensive tackle spot, he erupted with 18.5 tackles behind the line of scrimmage and 7.5 sacks. 

Blessed with a dangerously quick first step and loose hips, Broughton threatens interior blockers on basically every snap. He flashed some pass-rushing moves, but mostly wins with legitimately one of the most impressive get-offs I watched of any interior defensive linemen in the entire 2019 class. 

Now, a major hurdle he'll have to clear early on is the fact that he was picked in Round 7. And Round 7 picks aren't exactly first in line to get reps in camp. He needs to make the absolute most of the snaps he's given, even if they're with the second or third team, to start. The likely limited action at the outset of his first NFL camp will make it difficult for Broughton to make an impact. But based on his springiness off the ball, smooth lower half, and the Chargers' dire need to create pressure from the inside of their defensive line, Broughton has a much better opportunity to make the team and see time in 2019 than the majority of seventh-round rookie defensive linemen. I envision him being utilized in nickel packages as a pass-rushing specialist.