CORONA, Calif.-- GEICO Honda's Zach Osborne will undergo surgery Thursday to repair a torn ulnar collateral ligament in his left thumb, which he injured in the second moto of the Lucas Oil Pro Motocross season opener Saturday in San Bernardino, Calif. He is expected to miss a minimum of eight weeks

"I'll try to get a few rounds in at the end of the season," a disappointed Osborne said from his home in Abingdon, Va. "I'm really bummed because I was ready to fight for the championship this year. Practice had been going great and I've felt good on the bike.

"It happened in the first turn of the second moto when everyone got stacked up. It's a high-speed area and I was riding my line, but someone came across my front and took my bike out. My momentum carried me forward over the bars and just ripped my thumb all the way back. There really wasn't anything I could do."

Doctors tell Osborne he won't be able to ride again for at least six weeks, but he's determined to push his rehabilitation as hard as possible so he can return to action.