CHARLOTTE, N.C. -- Carolina Panthers running back DeAngelo Williams isn't expected to play in Sunday's game against the Cleveland Browns unless it's an emergency situation.

Carolina's all-time leading rusher, who suffered a fracture in his right hand three weeks ago at Minnesota, has been fitted for a playing cast. But coach Ron Rivera said Friday concerns remain that Williams will be able to effectively use the hand, primarily in pass protection.

Linebacker A.J. Klein also is listed as questionable with an ankle injury, but Rivera was optimistic he would play.

Meanwhile, Rivera said the team will make a decision either Saturday or Monday on whether to activate defensive end Frank Alexander to the active roster. Alexander missed the first 14 games for two separate violations -- four and 10 games -- of the NFL's substance abuse policy.

Rivera said Alexander has looked good in practice and has shown things that could help the defense if he is activated for the Browns. The decision will depend on roster numbers, with Rivera noting other players on the defensive front have played well the past few weeks.