When the Lions were on a bye last week, 19 players missed practice before the team was let go to enjoy a weekend off. Upon returning to practice on Tuesday, the number of players out was down to only two. During the bye, the Lions had the luxury of letting players even a little banged up take time off to recover. There are undoubtedly still some players dealing with injuries, but the good news is that only two are severe enough to keep guys out of practice altogether.
The two players that missed all of practice were Shaun Hill and Zack Follett. Hill broke his left forearm against the Giants and had surgery on it last week, so he likely won't be back anytime soon. Follett suffered a neck injury in the same game and is set to meet with a specialist later this week. It's possible his injury could keep him out for an extended period of time (perhaps the rest of the season), but the Lions won't know for sure until he meets with the specialist. (Bobby Carpenter, who signed last week, is expected to take Follett's place in the starting lineup.)
While only two players were completely out of practice, some were limited because they are still dealing with injuries, including Kyle Vanden Bosch, Turk McBride, Bryant Johnson and Jahvid Best. Best, for example, is still recovering from a nagging toe injury. The Lions don't want him to reaggravate the injury, so he only did some stuff on the sideline with the conditioning coaches. Most or all of these players likely will be able to play on Sunday, but there's no reason to risk further injury during practice, as an extra day or two to recover may be all that they need.
Another player that was limited on Tuesday is DeAndre Levy. Levy has basically been out of practice for all but a week or so of the season. Although he was limited on Tuesday, the good news is that he was actually back on the practice field. He hasn't even thought about practicing in weeks, but it appears he is progressing from his various injuries. It's unclear if he will actually be able to play on Sunday, but at least this week it appears to be possible.