Stewart is out of San Francisco after wrist surgery.

Team San Manuel Yamaha’s James Stewart underwent surgery today to repair a broken scaphoid in his right wrist, forcing him out of this weekend’s round in San Francisco this weekend.

Following round three of the 2010 Monster Energy AMA Supercross, an FIM World Championship, in Anaheim, CA, last weekend, Stewart continued to experience severe pain in the wrist.

Although previous X-rays had not indicated there was a break, an MRI performed yesterday and reviewed by medical experts today, revealed the bone was broken.

Surgery was performed immediately by orthopedic surgeon Dr. Arthur Ting, of Fremont, CA and was completed without incidence.

As a result of the surgery, Stewart will not be competing in San Francisco this weekend. His return to the race track will depend on how quickly he is able to recover post-surgery and will be evaluated and determined on a weekly basis.

“James is a true champion. The fact that he rode as competitively as he did making the podium at Anaheim 2 with a broken wrist is testimony to that,” said team manager Larry Brooks. “He’s anxious to heal and get back on the race track as soon as possible.”

The news means that two of the most recent series champions Stewart and Australia’s Chad Reed are effectively out of the point chase, leaving Rockstar Makita Suzuki rookie Ryan Dungey as the series favourite after two commanding victories at Phoenix and Anaheim 2.