Le'Veon Bell took a shot on his right knee by Bengals safety Reggie Nelson in the third quarter of the Steelers' eventual 27-17 win.
As soon as Bell went down, it was clear he was hurt badly. Even Steelers coach Mike Tomlin appeared especially concerned, seeing the team's MVP writhing on the ground.
The injury is being listed as a hyper-extension of his right knee and, according to Tomlin's post-game press conference, "structurally, it appears to be ok." That suggests there are no ligament tears, which would be the worst-case scenario.
But that doesn't mean Bell is in the clear. With a short week - they'll play the sixth-seeded Ravens on Saturday night - he may need quite a bit of luck to get on the field in the franchise's fourth meeting with the Ravens in the playoffs.
Bell, the team's MVP this season, finished the year with 1,361 yards, second in the NFL. He led all running backs with 83 receptions, a club record for running backs, and he was named to his first Pro Bowl team.