The Browns had high hopes for Solomon, who emerged after being signed to the team's practice squad in November. The Browns especially liked Solomon as a run-stopper.
But he was on the field for two plays in the loss to the Jets before he was injured.
Barkevious Mingo took over, but Mingo was playing in his first game after having arthroscopic right knee surgery Aug. 6 and was on the field for just 13 snaps.
With Solomon out, the Browns probably will have to make a move to add another outside linebacker.