Pettigrew injured his ankle in Week 15 against Baltimore and did not practice last week or play against the New York Giants on Sunday.
"It's interesting the way the tight ends have gone on both teams," Detroit coach Jim Schwartz said. "[Minnesota] lost [Kyle] Rudolph, and then they just lost [John] Carlson. You'd like to have more than one tight end.
"We used some offensive linemen in there. They've used some four-wide-receiver stuff. Each team has challenges. We would use that roster spot somehow."
Pettigrew caught 41 passes for 416 yards and two touchdowns this season and will be an unrestricted free agent after the season.
Detroit is now down to one healthy tight end, Joseph Fauria, as Dorin Dickerson suffered a concussion Sunday against New York and has yet to be cleared. To replace Pettigrew, the Lions could promote Matt Veldman off the practice squad or sign another player.