Best case for return is six weeks
The 31-year-old right-hander met with Dr. Lewis Yocum on Saturday and will have the operation next week. A date and place had not been determined.
"The best-case scenario is six weeks," Zimmerman said. "This is actually a relief because it's going to give me piece of mind to know one way or the other."
Zimmerman has had two reconstructive surgeries on the elbow and has not pitched in a major league game since Oct. 7, 2001.
He reinjured the elbow in a "B" game on March 14 against Seattle.
Zimmerman has been going through extended rehabilitation since the injury, consisting of a lot of icing to reduce the inflammation that has left a golf ball-sized knot on the inside of his elbow.
"I'm just happy that something is being done," Zimmerman said. "I just want to know what is going on at this point."
The injury is the latest setback in his bid to find the form that made him an All-Star as a rookie in 1999.
He won his first nine major league decisions that year and had 28 saves in 2001, sixth-best in the American League.
Copyright 2004 by The Associated Press