ALLEN PARK — The Lions do have an interest in free agent linebacker Keith Bulluck, coach Jim Schwartz said on Thursday.

Bulluck tore his ACL on Dec. 20 and is coming off surgery. The linebacker played for Schwartz when he was defensive coordinator with the Tennessee Titans. The Lions have lost two linebackers — Ernie Sims and Larry Foote — in the offseason.

“I don’t know where he is physically, what he says or what his agent is saying where he is,’’ Schwartz said. “He is a guy, among others, we’ve had our eye on.

“It just throws a little bit of a monkey wrench into it for him coming off an ACL. He’s a quality player that’s played for a long time in the NFL. When he’s available, I’m sure there will be a lot of teams interested in him,’’ Schwartz added.

The Lions have a few players coming off ACL surgery — Brandon Pettigrew, Kevin Smith, Jack Williams — and while they participate in individual OTA drills, they have not been cleared for full practice. Schwartz said he expects Bulluck might be on the same timetable. Schwartz said Bulluck is a multi-dimensional linebacker (Schwartz’s favorite kind of player) and could play at any spot. He said while with the Titans Bulluck played mostly on the right side and was the middle linebacker in the nickel package.

Lions general manager Martin Mayhew has been aggressive at signing free agents and making trades to improve the roster and apparently he’s not done yet.

“Sometime between the draft and opening day we’re going to add players that are going to help us win a game,’’ Schwartz said.

One of them could be Keith Bulluck. (Follow me on Twitter @PaulaPasche.)