General manager Ruben Amaro Jr. says the veteran righty will have exploratory surgery to determine whether the problem in his elbow is muscular or a tendon injury. Amaro says Contreras doesn't have ligament damage.
Contreras, who has been sidelined since late June with a right forearm strain, had five saves and a 3.86 ERA in 17 games this season.
The major league-leading Phillies have used four closers this season because of injuries.
