ST. LOUIS -- The Pittsburgh Steelers face the possibility of quarterback Ben Roethlisberger missing time after he injured his left knee and was carted off the field in the third quarter, overshadowing their 12-6 victory over the St. Louis Rams. Roethlisberger was seen leaving the locker room on crutches.

Though the severity of the injury is not yet known, Roethlisberger is expected to miss at least four weeks, a source told ESPN NFL Insider Adam Schefter.

It doesn't help that the Steelers are on a short week, hosting the Baltimore Ravens on Thursday.

It’s a good thing the Steelers signed Michael Vick, who was 5-of-6 for 38 yards. Vick won't put up Roethlisberger's gaudy numbers, but he's a veteran who should take advantage of Pittsburgh's many offensive weapons. One of those weapons returned from a two-game suspension, as Le'Veon Bell gained 62 yards and a touchdown on 19 carries while also catching seven passes for 70 yards.

Big play: Pittsburgh safety Will Allen picked off a Nick Foles pass with 2:51 left in the game.

What were they thinking?: Cornerback Antwon Blake wrestled with Rams receiver Kenny Britt on a play down the left sideline and received an interference penalty to set up the Rams’ second field goal of the game. The ball went from the Rams' 35 to the Steelers' 31.

One reason to be excited: Bell didn't have a huge game, but his all-around contributions were evident. His return and the return of Martavis Bryant in Week 5 are big reasons to be excited. Another reason is the continued dominance of receiver Antonio Brown, who had 11 catches for 108 yards.

One reason to panic: The sight of Roethlisberger lying on the ground holding his left knee.

Fantasy watch: Folks who had running back DeAngelo Williams active as the result of his performance through two games were disappointed. He had one carry for 2 yards.

Game ball: Brown torched the Rams for 11 catches and 108 yards.