Just got a call from MLB.com’s Phillies beat writer, Ken Mandel. He’s reporting that first baseman Jim Thome will miss the remainder of the season.

Thome has opted to have season-ending surgery on his right elbow to clean out what has been termed a “fraying” of the tendon. He’ll have the procedure performed by Dr. James Andrews on Tuesday in Birmingham, Alabama.

It’s a big blow for the Phillies, who are in the thick of the National League Wild Card race. Prospect Ryan Howard has stepped up in Thome’s absence, but he had also become a valuable trading chip.

Now the Phillies won’t be able to trade Howard in the offseason, and not many teams will want Thome, who has a big contract and is coming off a serious injury.