Reading a tweet from Scott Brown at the Pittsburgh Trib: @ScottBrown_Trib after talking to Steelers lineman Trai Essex.

Sounds like Starks tore ACL in Den. Essex said, "I know he's devastated, especially going through a free agency year but he'll bounce back."
As you remember, Starks came back on a 1 yr. deal, so he will be unrestricted once the free agent period starts in a couple of months. The Steelers have a big decision to make with Starks here and this ACL injury (if it indeed does turn out to be a tear). Max tweeted yesterday, that he will need surgery and rehab but there's been no official word on the severity of the injury or any timetable for rehab and a return to football.

maxstarks78 Max Starks IV

gotta get surgery and rehab before I explore the world! I'm sure you're playing at like 11 or noon my time!