BY RICH CAMPBELL

Washington Nationals third baseman Ryan Zimmerman had surgery Wednesday to remove a bone fragment from his left wrist.

Zimmerman broke the hamulus, or "hook," of his hamate bone on Sunday while swinging a bat with some friends at his high school in Virginia Beach.

The bone fragment was successfully excised by Dr. Richard Barth at Sibley Hospital in Washington, the team said yesterday.

Zimmerman will wear a splint on his wrist for approximately one week, at which time he will have the sutures removed and begin rehabilitation.

Prior to surgery, Zimmerman said that the injury was caused by "wear and tear" and that he had experienced minor, nagging wrist pain for several years. He expects to be fully healthy in four to six weeks, and his normal offseason routine should not be dramatically affected.

Carpenter will be back with TV broadcast

Bob Carpenter, the Nationals' television play-by-play broadcaster for the last two seasons, will return for the 2008 season, Mid-Atlantic Sports Network announced yesterday.

The Nationals told Carpenter in September that they were looking for his replacement, and Carpenter said during the final homestand that he believed his tenure would end at the conclusion of the regular season.

The Nationals, however, were reportedly turned down by ESPN's Dan Shulman and apparently had a change of heart regarding Carpenter.

"It is the nature of the business," Carpenter said by phone last night. "To me, it's all water under the bridge. I'm not going to worry about what happened during September. I'm happy to be back, and I'll try to do the best job I can. I don't think it will be awkward at all."

Carpenter signed a one-year contract with a team option for 2009, he said. He thanked fans who voiced their support to the team and network.