NFL Network reported X-rays on Roethlisberger's ankle were negative. He was throwing on the sideline before the start of the second half and limped onto the field for the Steelers' first possession.
Roethlisberger's knee buckled when he was brought down by Browns defensive lineman Scott Paxson, who grabbed the two-time Super Bowl-winning quarterback by his left leg. After laying on his back at his own 10-yard line for several minutes, a grimacing Roethlisberger was helped by two trainers as he hobbled off the field and then got carted into the locker room.
Roethlisberger left with 5:59 left in the second quarter and the Steelers leading, 7-3. He completed eight of nine passes for 102 yards and one touchdown.
Longtime backup Charlie Batch replaced Roethlisberger, who has dealt with a foot injury and broken right thumb this season.
Jamison Hensley is the AFC North blogger for ESPN.com.