In his first three NFL seasons, Nick Fairley has been brilliant at times and invisible at others.

The challenge for new coach Jim Caldwell and his staff is to get more regular production out of one of the most talented but perplexing defensive tackles in the league.

“He could play more consistently,” Lions general manager Martin Mayhew said Monday night at the Senior Bowl. “I mean, he's got to mature a little bit as a professional, I think. I think that'd be a big step in him playing more consistently.”

Fairley has dealt with questions about his conditioning and motivation since he left Auburn early for the 2011 draft and slipped out of the top five to the Lions at pick No. 13.

He broke his foot his rookie year and missed half the season, separated his shoulder late in 2012 and finished the year on injured reserve, and didn't dominate enough this year while his running mate, Ndamukong Suh, drew regular double teams and he played the season at nearly 320 pounds.

Asked Monday if Fairley's weight is an issue, Mayhew said, “I wouldn't say his weight is too high.”

So what would Mayhew say?

“He could probably re-position some of that weight,” Mayhew said.

If there's incentive out there for Fairley to take better care of his body, it could be his contract, which is currently set to expire after next season.

The Lions have until May 3 to exercise the fifth-year option on Fairley's contract, a standard provision for all first-round picks under the collective bargaining agreement signed in 2011.