Tillman suffered a torn triceps muscle in the same arm last November, and the setback resulted in the team placing the cornerback on the injured reserve with a designation to return.
Tillman sustained the injury in the third quarter, when he appeared to become tangled up with a 49ers player near the sideline. Immediately after the injury, head athletic trainer Chris Hanks and a team physician ran tests on Tillman, who appeared to be in considerable pain.
A 12-year veteran and two-time Pro Bowl selection, Tillman (152 career starts) ranks third in franchise history with 36 interceptions. Tillman leads the franchise in career interception return yardage (675), interception return touchdowns (eight) and defensive return touchdowns (nine).
Tillman leads the NFL with 42 forced fumbles since 2003. Tillman is also the only player since 2003 to record 40 forced fumbles and 30 interceptions.
Tillman, 33, signed a one-year contract back in March worth $3.5 million. The Walter Payton NFL Man of the Year in 2013, Tillman played in just eight games last season before suffering the torn triceps.
In other injury news, safety Chris Conte (shoulder), cornerback Sherrick McManis (quadriceps), defensive end Trevor Scott (foot) and defensive tackle Jeremiah Ratliff (concussion) have been ruled out due to injuries.