PITTSBURGH — Pittsburgh Steelers outside linebacker James Harrison has been cleared to play against San Francisco this week despite being carried off the field on a stretcher during Sunday's game against Buffalo.

Coach Mike Tomlin said Tuesday the news on Harrison was "very good" and that Harrison was diagnosed with a stiff neck.

Harrison may be held back during practice today, but can play Sunday, Tomlin said.

Harrison was hurt on Marshawn Lynch's 8-yard carry that ended the second quarter.

Harrison, caught in a pileup, rammed his head into teammate Casey Hampton's back as Lynch was tackled by Brett Keisel and Clark Haggans. He lay motionless briefly as the Steelers delayed a halftime tribute to some of their former stars until Harrison was taken off the field.

After being examined by doctors for a few minutes, Harrison returned to the sideline midway through the third quarter, but did not play again.