CLEVELAND -- Pittsburgh Steelers wide receiver JuJu Smith-Schuster exited Thursday night's game against the Cleveland Browns in the second quarter after absorbing two helmet-to-helmet hits. Smith-Schuster was ruled out for the rest of the game with a concussion before halftime.

Running back James Conner, who reinjured his shoulder in the second quarter, was also ruled out, along with wide receiver Diontae Johnson (concussion), cornerback Artie Burns (knee) and linebacker Ola Adeniyi (concussion).

Johnson left the game in the third quarter after he was hit while in a defenseless position by Browns safety Damarious Randall. Randall was ejected for the hit.

Smith-Schuster caught a pass from Mason Rudolph over the middle and was immediately hit in the head by Greedy Williams. A split second later, he took another helmet-to-helmet hit by safety Morgan Burnett.

Smith-Schuster dropped the pass and lay face-down and motionless for at least a minute. Trainers rushed out to evaluate him and a couple Browns players took a knee near him. A trainer carrying a backboard came out, but it wasn't needed. Smith-Schuster, 22, was able to walk off the field on his own, albeit slowly, and went directly to the locker room.

At the time of Smith-Schuster's injury, the Steelers were already without Conner and struggling offensively.

Pittsburgh sputtered even more without its top playmakers. Smith-Schuster had two catches for 21 yards -- including one 16-yard gain -- when he went out, and Conner had five carries for 10 yards.