[
](http://www.embarque.com/)
INDIANAPOLIS –We move over to the defensive side of the football in our burning questions series.
The men in the trenches might be the most closely watched group of any in 2015.
Here's a look at the defensive line burning questions heading into the team's offseason program.
- What's in store for Arthur Jones in his second season with the Colts?
Hobbling off the field during the Colts Week Two Monday night game last season wasn't how Arthur Jones pictured the start of his first season in Indianapolis.
His return to the starting lineup didn't come for another three months and the Colts most important free agent signing from 2014 (outside of Mike Adams) was never the same player.
When Jones did return for a stretch to close out the 2014 regular season, the Colts defense had some of its strongest outings.
The AFC Championship game remains the most vivid memory from last season, but the Colts run defense was improved when Jones was in the lineup.
His health in 2015 is vital for any improvement in the trenches.
Outside of the nose tackle position, Jones is the only defensive line returnee from last season who has been asked to play meaningful minutes in the NFL.
As the Colts continue to build their run defense, Jones is the centerpiece of that process.
I think you could argue that outside of Andrew Luck and Vontae Davis, Jones might be the most important player to the Colts reaching the pinnacle next season.
STAT TO NOTE: Arthur Jones' 55 career games played is nearly double that of any returnee on the Colts defensive line.**
**
- Who fills the rolls vacated by Cory Redding and Ricky Jean Francois?
In losing Cory Redding and Ricky Jean Francois, the Colts have more than 1,300 defensive snaps from last season that must be replaced.
That's a very high number for a position group that rotates so many bodies.
The first man who will take a bulk of those reps will be new free agent addition Kendall Langford.
In Langford, the Colts are getting much bigger (6-6, 314 pounds) and hopefully more durable.
After six years as a starter in the NFL, Langford was a reserve for the St. Louis Rams last season.
He feels the return to a 3-4 scheme (played in a 4-3 defense the last two years with the Rams) will spark his play this season.
Langford's production as a probable starter is obviously the key, however his stability in the lineup (112 straight games played, the most of any defensive lineman in the NFL) is just as important for a unit that has recently battled injuries.
Besides Langford, young linemen in Zach Kerr, Montori Hughes, and Kelcy Quarles will all be asked to take on expanded roles in 2015.
STAT TO NOTE: As an undrafted free agent in 2014, Zach Kerr finished the year in the top 10 among all rookies with 3.0 sacks.**
**
- Will defensive line depth be added in the draft?
As the Colts have assembled one of the best young offenses in the NFL through the draft, the defense could now be the recipient of several picks in 2015.
The Colts transition from a far end 4-3 defense, to a 3-4 scheme with the proper personnel has taken some expected time.
Adding a young piece up front to that defense could be an early benefit come draft time.
Listening to general managers talk at the NFL Combine, many of them praised the interior defensive linemen at the top of this year's class.
Several mock drafts have around a handful of defensive linemen going in the latter half of the first round.
Take a look at the levels of the Colts defense and hardly any youthful bodies have been drafted (a result from the, talented, offensive picks that have dominated the last three drafts).
Ryan Grigson and Chuck Pagano have continuously talked about improving the trenches this offseason.
That could very well come early in the draft.
STAT TO NOTE: Since 2010, Bjoern Werner is one of just two defensive players the Colts have drafted in the first four rounds (Drake Nevis, the other).