Browns free safety Brodney Pool was placed on injured reserve Wednesday night after suffering the fourth concussion of his five-year career Sunday at Cincinnati.
Pool, 25, may have to consider retirement because of his concussion history, but coach Eric Mangini said he had not discussed that with Pool.
Pool leads the Browns with a career-high four interceptions, along with 48 tackles, 10 passes defensed and one sack in 11 games (10 starts).
''I was encouraged with Brodney's progress each week and appreciated his approach and attitude towards this season,'' Mangini said in a statement. ''Through 11 games he had already reached his career-bests for interceptions and passes defensed.''
Pool was one of four Browns defensive players to get hurt in the game against Cincinnati, with defensive lineman Shaun Rogers (left leg/ankle injury) having already been placed on injured reserve. Rogers will need surgery.