Philadelphia Phillies backup catcher Erik Kratz was placed on the 15-day disabled list Sunday in Milwaukee with a left leg injury. An MRI Monday revealed that he will need surgery on his left knee to repair a torn medial meniscus.
The length of recovery for Kratz won't be known until he has surgery.
Carlos Ruiz, the team's starting catcher, has already been on the disabled list since May 21 with a hamstring injury.
The Phillies are now down to their third and fourth catchers on the depth chart: Humberto Quintero and Steven Lerud.
Ruiz isn't due back for at least another week.
"Losing Kratzie hurts us," manager Charlie Manuel said. "He was playing good and hitting some big home runs for us. He was doing most of our catching."
Kratz was hitting .229 with eight home runs and 22 RBIs before getting hurt.