INDIANAPOLIS -- The start of training camp is still more than three months away, leaving plenty of opportunities for things to change for the Indianapolis Colts. But they finished up their heavy lifting in free agency when they signed former Atlanta Falcons safety Dwight Lowery on April 3.

Let’s take a look at how the starting defensive unit could look in Week 1, depending on position battles and health.

2014 DEFENSE

Total: 11th

Pass: 12th

Run: 18th

Strength: Cornerbacks Vontae Davis and Greg Toler

Weakness: Pass rush and stopping the run

2015 PROJECTED DEFENSE

Defensive end: Kendall Langford

How acquired: Free agent 2014

2014 stats: 25 tackles, 1.0 sacks

Note: Langford had a down year last season, but said he’s definitely more comfortable in a 3-4 defensive scheme than a 4-3 scheme, which he played with the St. Louis Rams.

Nose tackle: Josh Chapman

How acquired: Draft 2012

2014 stats: 21 tackles, one forced fumble

Note: Chapman gets the nod here only because he started 15 games last season. But you can expect Montori Hughes and Zach Kerr to push Chapman for the starting job.

Defensive tackle: Art Jones

How acquired: Free agent 2014

2014 stats: 23 tackles, 1.5 sacks, one forced fumble

Note: The biggest question surrounding Jones is whether he can stay healthy. He missed seven games last season with a high ankle sprain.

Outside linebacker: Robert Mathis

How acquired: Draft 2003

2014 stats: Suspended/injured reserve

Note: There is no guarantee Mathis will be ready for the start of the season. Trent Cole, who the Colts signed last month, is the likely candidate to start here if Mathis isn’t fully recovered from his torn Achilles. Cole has 85.5 sacks in his career.

Inside linebacker: Jerrell Freeman

How acquired: Free agent 2012

2014 stats: 94 tackles, 1.5 sacks, six passes defended, one forced fumble

Note: The Colts tendered a qualifying offer to Freeman on March 5. They can match any offer the linebacker receives from other teams. Freeman, who led the Colts in tackles in 2012 and 2013, has until April 24 to sign an offer sheet with another team.

Inside linebacker: D'Qwell Jackson

How acquired: Free agent 2014

2014 stats: 140 tackles, 4.0 sacks, one forced fumble, four fumble recoveries, one touchdown

Note: Jackson, who is coming off a Pro Bowl appearance, had his sixth season of at least 100 tackles, finishing with a team-high 140 tackles last season.

Outside linebacker: Erik Walden

How acquired: Free agent 2012

2014 stats: 37 tackles, 6.0 sacks, one forced fumble

Note: On the team, his six sacks were second only to linebacker Jonathan Newsome's 6.5 last season.

Cornerback: Vontae Davis

How acquired: Trade 2012

2014 stats: 42 tackles, four interceptions, 19 passes defended, two forced fumbles, one fumble recovery

Note: Davis lived up to the four-year, $39 million contract the Colts gave him in 2014 by becoming one of the premier cornerbacks in the NFL last season.

Cornerback: Greg Toler

How acquired: Free agent 2013

2014 stats: 57 tackles, two interceptions, one sack, 10 passes defended,

Note: Toler shook off his injury-prone label by playing a career-high 15 games last season and teaming with Davis to give the Colts a solid cornerback duo.

Safety: Mike Adams

How acquired: Free agent 2014

2014 stats: 87 tackles, five interceptions, 11 passes defended, two forced fumbles, two fumble recoveries

Note: Adams was the backbone of the secondary and the team’s second-best defensive player behind Davis last season. Adams' seven takeaways tied for the league lead.

Safety: Dwight Lowery

How acquired: Free agent 2015

2014 stats: 79 tackles, two interceptions, 1.0 sack, five passes defended, two forced fumbles, one fumble recovery

Note: Lowery has the inside track to start. He does have a history of concussions. He suffered the third concussion of his NFL career last season while with the Atlanta Falcons.