JACKSONVILLE, Fla. -- The Jacksonville Jaguars were one of the healthiest teams in the league over the first 10 weeks of the season.
No starters on injured reserve. Only a few backups out for the year. It one was one of the lone bright spots in an otherwise dismal season for the franchise.
Mathis tore the anterior cruciate ligament in his left knee in Sunday's 17-3 win at Indianapolis and will have season-ending surgery. Britton, who missed the last four games, developed an infection following back surgery in training camp. Bosworth broke his left hand against the Colts.
"It's life in the NFL," coach Jack Del Rio said Monday. "It's a tough business. It was nice to get a win. Tough for a couple guys to get news that they're going to go on IR, but as a football team we're going forward doing the best we can."
Losing Mathis is the biggest setback for the Jaguars (3-6), and it could mean he has played his last game in Jacksonville. Born and raised in Jacksonville, Mathis is in the final year of his contract. It's unclear whether the team will give the 31-year-old defender who has missed games in four of the last five seasons a new deal.
Mathis was playing arguably his best football, with 12 passes defended and an interception this season. He injured his knee while planting to cover Colts receiver Pierre Garcon.
"It's unfortunate," Del Rio said. "He's a good football player. He's having a good year for us and so obviously, as we do, we move on as a team."
Mathis has started 125 games -- every one he's played since being drafted in the second round in 2003 -- made the Pro Bowl in 2006 and was the leader of the team's revamped secondary. Without him, Will Middleton will move into a starting role.
"That's a huge loss," defensive end Jeremy Mincey said. "That's a veteran voice we need out there. We've got guys that have to step in and pick up where he left off and grow up, hopefully do the same thing he did."
Despite Mathis' injury, Jacksonville won for the second time in three games and kept alive slim hopes of winning the AFC South. The Jaguars dominated the Colts, scoring points on one of Curtis Painter's two interceptions and turning backup Dan Orlovsky's fumble into a late touchdown that sealed the game.
But injury news kept the Jaguars from celebrating.
Mathis had X-rays in Indianapolis and tests Monday revealed the severity of the knee injury.
"With us being a young defense, a lot of players look up to him for guidance, just for the type of ability that he has," cornerback Drew Coleman said. "When we come to the sidelines, we discuss things and it's kind of like he has the last say on how we do certain things during certain plays. ...
"The confidence is there within our group that we'll pick it up and replace him. In this league, you're always one play away from being a starter. Now that that opportunity is there, we'll step up and fill that role. We won't miss a beat, but we'll miss his leadership. We'll miss looking up to him for guidance. We'll truly miss him, but we have young guys who are ready to take advantage of this opportunity."
The Jaguars expect to work out several cornerbacks Tuesday.
The team also signed second-year tight end Fendi Onobun off Washington's practice squad and added tight end Colin Cloherty to the practice squad. The team also waived rookie tight end Schuylar Oordt from the practice squad.
The moves left Jacksonville with two open roster spots, which could be used to replace Britton and Bosworth.
Bosworth was one of the team's top special teams tacklers.
Britton missed the entire preseason and the opener because of a herniated disk in his back. He started three games, but his back tightened up the morning of the Oct. 16 game at Pittsburgh and he hasn't played since.
"The complications he's having, they're not structural, but it's going to require some time and so he's not going to be available for us," Del Rio said. "So another unfortunate situation with him being a good football player and a guy that we were hoping to get back. But he's not going to be able to make it and so he'll go on IR as well."