Lamar Jackson left for the locker room in the third quarter as the Browns were driving for what turned into a touchdown.
The Ravens quarterback has leg cramps, according to the team, and is questionable to return.
He presumably went into the locker room for an IV.
The Ravens lead 34-28 with 13:36 remaining in the fourth quarter with Trace McSorley entering the game.
Jackson has completed 6 of 11 passes for 81 yards, and he has run for 124 yards and two touchdowns on nine carries. That is the most rushing yards ever for a quarterback on Monday Night Football.