Reports confirm that, Sulley had the operation on Monday and will absent for close to a month.
The 23-year-old suffered the injury during Steaua Bucuresti’s 2-0 defeat at CFR Cluj two weeks ago in the Romanian top-flight.
He was replaced on 82 minutes by Nicandro Breeveld after the problem.
As a result, Sulley sat out Steaua’s 5-3 win over FC Botosani on Sunday.
Sulley, a summer signing, has made ten league appearances and scored one goal this season for the Romanian champions.