Pitta went to the locker room to be examined after being shaken up on a tackle by free safety Ryan Clark and linebacker Lawrence Timmons.
For the season, Pitta has 38 receptions for 381 yards and three touchdowns. That includes one reception for five yards against Pittsburgh.
Steelers running back Isaac Redman (Bowie State) left the game with a concussion and defensive lineman Ziggy Hood left with a back injury.
Out of football since being cut during the offseason by the Raiders, newly-minted Ravens cornerback Chris Johnson got up to speed in a hurry on the basic details of defensive coordinator Dean Pees' playbook.
Signed to a one-year, $825,000 contract last Tuesday following a successful tryout, Johnson was able to put that knowledge to use against the Steelers as he forced a fumble that led to 26-yard Justin Tucker field goal.
Johnson left the game after tweaking his hamstring, but indicated it wasn't serious and wasn't limping after the game in the locker room.
"I came down wrong," Johnson said. "It's all good. It's just strained a little bit."
Johnson, 33, entered the game cornerback in the second defensive series when the Ravens came out in the nickel package, lining up outside as Corey Graham shifted inside to play the slot receiver.
The 6-foot-1, 200-pounder stripped wide receiver Emmanuel Sanders from behind with free safety Ed Reed picking up the loose football and returning it 17 yards to the Steelers' 12-yard line.
"I've been doing this for a long time," said Johnson, who has eight career interceptions. "I take boxing lessons, so that's a jab from me. Once I seen him cut across my face, I just wanted to get my hands in there and I knew I knocked the ball out."
Reid gets the start
Left offensive guard Jah Reid started the first game of his NFL career one week after playing all but two series against the Raiders in relief of veteran Bobbie Williams.
The 6-foot-7, 330-pounder worked almost exclusively with the first-team offense during practice last week.
Although Reid delivered a solid block a week ago against the Raiders on Pro Bowl running back Ray Rice's touchdown run, he faltered early in the game against Pittsburgh.
Steelers defensive end Brett Keisel got past Reid with a quick move to deck Ravens quarterback Joe Flacco in the first half.
"I want to acknowledge the first play was terrible," Reid said. "I had some good plays and bad plays. I played hard. Hopefully, I didn't disappoint the coaches. I'll give Keisel credit.
"It wasn't a missed assignment. He just beat me fair and square. I learned from it and I tried not to let it hapepn again in the game."