Silas was injured Friday in Orlando, Fla., when he took an inadvertent elbow to the head by teammate Solo Jones. Silas also suffered a concussion.
The Sixers say Silas needs surgery Saturday where doctors will fuse several frontal sinus fractures. There is no timetable for his return.
Silas did not appear in any regular season games with the Sixers after signing with them in April.
Silas tried to block a shot against the Pistons on Friday when Jones made contact with the head. Sixers guard Evan Turner wrote on Twitter that he spoke with Silas and "Thank god he's alright."
He went undrafted after playing at collegiately at Colorado and Northern Illinois University.