There's never a good time for an ACL tear.
And with it, he mentally began preparing for a long and grueling rehabilitation, commonly as long as nine months to a year from the injury. It came before the playoffs, before the Steelers hired a new offensive coordinator and before the last year in Mendenhall's contract.
All of those things make a bad injury even worse.
Steelers GM Kevin Colbert told reporters Monday Mendenhall could start the season on the physically-unable-to-perform (PUP) list, meaning he would hold an exemption against the Steelers' 53-man roster.
It would also mean he's not 100 percent ready to play, and he would watch the carries he used to get go to the talented and much less expensive Isaac Redman. He'd also have to watch two younger backs, Jonathan Dwyer and John Clay (both of whom had carries this season), continue to develop.
Perhaps worst of all, he may have to watch the Steelers re-sign veteran Mewelde Moore as insurance to Mendenhall's knee. Moore, a shifty back with good receiving skills, could get a boost in production from new offensive coordinator Todd Haley's offense. With the Chiefs, Haley used his running backs as multi-purpose weapons - a role in which Mendenhall would likely thrive as well - and without those early training camp reps, Mendenhall may find himself behind the 8-ball in a season he needs to produce to justify an extension.
It's not out of the realm of possibility for the Steelers to draft a running back fitting that description, either. Dwyer and Clay are bigger, between-the-tackles kinds of runners. They have league experience, which always helps, but investing in a quick back with good hands may not cost them a high pick.
Those thoughts are probably circling Mendenhall's mind during his rehabilitation. Can't help but think if he was going to tear an ACL, he would have much rather done it in Week 4 than Week 17.