Tight end Brandon Pettigrew injured an ankle in the fourth quarter of Monday's loss to Baltimore and did not return.
He didn't take part in the team's jog thru on Wednesday, either, and head coach Jim Schwartz says his injury is the most concerning of all the Lions currently on the mend.
"We'll just see where he gets to over the course of the week," Schwartz said. "We'll have plans if he can play. We'll have plays if he can't."
It won't be easy to replace Pettigrew with anyone the Lions have currently on the roster, however. He's the most complete tight end they have and is their best blocker.
In fact, he had a number of terrific blocks in Monday night's game, including sealing the edge of
The Lions (7-7) have lost four of their last five games, which has allowed both Chicago (8-6) and Green Bay (7-6-1) to pass them in the NFC North standings.
Lions players and coaches have to feel they let a terrific opportunity to run away with the division slip through their hands when they were 6-3 and had just defeated Chicago for the second time this year.
"We let go of an opportunity to put these other teams away, we opened the door back for them," defensive tackle
"We let a bunch of ants in the house and now we have to go get an exterminator to get them out."
The Lions have win their remaining two games against the Giants and Vikings and hope Chicago and Green Bay lose one of their remaining two games to reach the playoffs. Chicago and Green Bay play each other Week 17.
"Being one down with two to play, it's not our ideal situation, but it's the hand that we play," Schwartz. "We are not dealt this hand, it's the hand that we're playing right now and the only thing that we concern ourselves with is the Giants."
"It's good, man. It's coming along," he said. "Just getting into the rhythm and trying to get healthy and come back as fast as a can. I'm just going to continue to keep working."
The timing of the injury couldn't have been worse for Slay, who was coming off his best performance of the year in Green Bay. He injured it on the practice field the week after Detroit's win over Green Bay on Thanksgiving.
"I feel like I had one of my best games and I wanted to continue because I felt like I had my swag coming back to me," he said. "It's going to stay here. I'm going to continue to get better."
Slay has missed the team's last two games.
Schwartz said Tuesday there was a chance Slay could return this week against the New York Giants. For that to happen, however, he'd likely have to return to the practice field at least once this week.
• Interesting note from the updated Pro Bowl voting this week. Quarterback Matthew Stafford trailed Indianapolis' Andrew Luck for the sixth spot in the voting by more than 11,000 votes in last week's totals. He trails by 1,197 in the most recent update. The player and coaching voting will still play a factor in the final tally, but the top six quarterbacks will make it.