ALLEN PARK — Nick Fairley’s goal is to get back before the end of the season.

Time is running out for the Lions defensive tackle with just three regular season games remaining, but don’t count him out.

“He’s certainly, I think you’ve probably seen him a round a little bit, you can tell his spirits are up, he’s improving which is great,’’ coach Jim Caldwell said on Thursday.

“He’s into a little different phase now in terms of the rehab, hopefully he continues to improve,’’ the coach added.

Fairley injured his knee in the Oct. 26 game in London and has not practiced or played since. The team opted for rest and rehab to see if the situation could be handled without surgery.

The defensive line has played well in his absence with C.J. Mosley starting and Andre Fluellen re-signed to help out.

“Obviously you just don’t find very many guys who are that big, that fast, that strong, that disruptive,’’ Caldwell said of Fairley. “Although we’ve been able to play quite well, C.J. has stepped in and played well. Flu has stepped in and played well.’’

Ndamukong Suh has also taken more snaps, at times more than Caldwell would prefer.

— Reggie Bush didn’t practice on Wednesday but was back on the practice field on Thursday. Clearly Bush is not done for the season.

Caldwell pointed out that a few weeks ago he was asked if we were seeing the demise of Calvin Johnson who responded with 304 receiving yards and three touchdowns in the last two games.

“I kind of like that question because I thought (Johnson) responded in a way that was appropriate,’’ Caldwell said. “You’re going to find Reggie will do the same at some point.’’

— Caldwell would not be more specific on the head injury to LaAdrian Waddle. He was listed on Wednesday’s injury report as limited in practice due to “head”. Caldwell would not say if that translates to concussion.

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