San Manuel Yamaha's James Stewart has been ruled out of the AMA Pro Motocross season opener.

Former national champion James Stewart has revealed that he’ll sit out the opening round of the AMA Pro Motocross Championship, which commences at Hangtown in Northern California this weekend.

The news broke this morning on Stewart’s official website at JS7.com, confirming that the San Manuel Yamaha team leader won’t be on the gates this weekend since he struggled in the closing stages of AMA Supercross.

“Everyone witnessed the way I struggled during the supercross series this year and while I’d like to race this weekend, we just aren’t ready,” Stewart admitted.

“I hope fans will understand. The decision has been very hard to make, but we won’t race till we’re ready.”

While Stewart’s not ruling out a return to the series, his absence at the season opener will create a huge point deficit for him to claw back against an all-star line-up that will include defending champion Ryan Dungey, new supercross champion Ryan Villopoto, plus Aussies Chad Reed and Brett Metcalfe.

Stewart has recently been spotted testing for the outdoors in California at a variety of tracks, today’s announcement coming as a surprising one following his disappointing season in the stadiums.

Stay tuned for further updates as we receive them from the U.S.