Editor’s note: This is the third story in a 10-part series looking at the most intriguing New England Patriots players ahead of training camp. Previously: Kyle Williams, Christian Gonzalez.At the start of Patriots minicamp, Mike Vrabel chose his words carefully when giving an attendance report.“Everybody under contract is here and accounted for,” Vrabel said.The catch? The team’s second-round pick, Gabe Jacas, remains unsigned in one of the most perplexing rookie contract disputes in recent years, one that leaves Jacas behind schedule as training camp nears and yields all sorts of questions about how much he’ll be able to contribute early in the season.That’s why Jacas, who still hasn’t practiced or participated in offseason workouts with the team, is one of the most intriguing Patriots players with training camp on the horizon.HistoryJacas is a first-generation American who grew up in Florida with Jamaican parents. At the start of his high school football career, he played on the offensive line before switching to become a pass rusher as a junior. He was also a wrestler who won a state championship in the heavyweight class.Jacas committed to play college football at Illinois and spent all four years of his collegiate career there, becoming a starter midway through his freshman season.He was mostly a stand-up edge rusher whose specialty was getting after the passer, even if NFL teams believe his size (260 pounds) and willingness will make him a well-rounded edge rusher as he develops. Jacas had 11 sacks and 13.5 tackles for loss as a senior.The Patriots traded up in the second round to select Jacas with the No. 55 pick.Why the Patriots traded for A.J. BrownChad GraffOffseason recapThis is where things got weird.Vrabel said this month that Jacas had a “procedure” but declined to get into any specifics and didn’t say whether the team knew about or approved it. Everything that has transpired raises questions about how much the Patriots knew about the injury before the draft and how much they agreed with the decision to undergo a procedure.Typically, teams don’t trade up early in the draft to pick players who are about to need surgery. Or if they do, they’ve already greenlit that kind of procedure and are willing to take on the risk and sign the player.But Jacas remains unsigned. Every second-round pick has signed his pre-slotted rookie contract except Jacas.Since spring practices begin so quickly after the draft, typically teams and drafted players will sign an agreement that essentially says the team will still sign the player even if he gets injured in spring practices. It gives assurances to the player while the sides hammer out the actual contract and allows the player to practice.But that never took place with Jacas. He has still never practiced with the Patriots. Outside linebackers coach Mike Smith admitted that Jacas is behind schedule because of this.Vrabel has remained upbeat about the situation, saying the Patriots will coach Jacas like they would any player once he shows up. But the fact that Jacas missed all of spring due to a procedure the Patriots are being coy about and remains unsigned is at the very least unusual, and at worst a troubling sign.X-factorThe Patriots need Jacas. They traded up because they couldn’t afford to leave the second round without getting help at edge rusher, which is probably their weakest position.And the other dilemma in all of this is that Harold Landry, who dealt with a lingering injury last season that required rehab this spring, didn’t practice in mandatory minicamp. Already, their depth is being tested. And Jacas was supposed to be a big part of that depth.Vrabel downplayed concern there, but it’s hard to see too much reason for confidence in the Patriots’ edge rusher spot through spring practices.“No, that’s a good group,” Vrabel said. “Again, we’ll continue to try to look at every position and make it stronger, but that group has done a nice job. We’ll continue to look at it, but we’ll have to see where we are at numbers-wise, and when we get into training camp just how many guys you can rep, based on the practices.”Reasons for optimismAll hope certainly isn’t lost just because of the strange start to Jacas’ career. There’s a reason the Patriots decided to trade up to pick him. He can be a menace in the backfield and has a knack for punching out the ball (he forced six fumbles in his final 25 collegiate games).Jacas is also a great athlete. He put up 30 reps on the bench press at the combine and ran a 4.65-second 40-yard dash at 260 pounds. That’s rare stuff.Plus, if the Patriots just use Jacas as a rotational pass rusher this season, that spot won’t require much complexity and understanding of the playbook. Will he start behind schedule? Sure. But if his main job is just to go get the quarterback, he can catch up pretty quickly.Reasons for concernThe Patriots used the No. 55 pick on a player they’re having a meaningful contract dispute with, who didn’t participate in spring workouts, who missed every full-team practice and who underwent an unknown procedure — and it’s not quite clear whether the team signed off on that surgery. All of that is pretty concerning.Jacas played in 50 straight collegiate games, and there’s certainly a path where he can put this strange start to his NFL career behind him. But this is not how you want to begin things with a player you thought was going to be a big part of your team in the coming years.What to watch in campThis one is simple. Is Jacas ready at the start of practice? If so, does the team limit his reps as punishment or because he doesn’t know the playbook? When does his contract actually get done?All of those are fair questions and worth following once training camp gets underway at the end of July.