Team USA will be minus a star rider at the 2013 Motocross of Nations (MXoN) in Germany, with the announcement that current AMA Pro Motocross 450 class leader Ryan Villopoto will undergo scheduled ankle surgery following next weekend’s final round.

Villopoto, who is on the verge of securing his second 450cc class title in three years, elected to have the surgery to remove a troublesome bone spur in his left foot.

Once complete, his focus will be on a return to full fitness in readiness for his pursuit of a record fourth-straight Supercross title in 2013.

“It is always a tough decision to go in and have surgery,” said Villopoto. “But just like my Monster Energy Kawasaki team works hard to give me the best bike possible, I have to make sure I’m at my best as well.

“The hardest part of this decision is the timing. I was really looking forward to racing the Motocross of Nations again this year, but I won’t be fully prepared in time for MXoN and I don’t want to give less than 100 percent to Team USA.

“The Motocross of Nations is always a highlight of the season and it is an event that has helped to define my career.”

Villopoto rides a 44-point lead to this weekend’s Utah National at Tooele, the penultimate round of the AMA Pro Motocross Championship.