Injured Yamaha rider Ben Spies will be replaced by Japanese test rider Katsuyuki Nakasuga for the final round of the 2012 championship in Valencia next month, the MotoGP team said on Sunday.
Spies had his Malaysian Grand Prix cut short last week following a heavy crash, after which the American was taken to the medical centre to check on a shoulder injury.
"Spies is currently at home in the USA recovering from injuries sustained in the Grand Prix of Malaysia one week ago." Yamaha said in a statement.
"The Texan had successful surgery this week to repair torn ligament damage in the right shoulder and will need a recovery period of eight to ten weeks," they added.
It was Nakasuga's second such call-up at Valencia where he finished sixth last year, substituting for injured Yamaha rider Jorge Lorenzo, who sealed his second MotoGP title on Sunday.
(Reporting by Amlan Chakraborty in New Delhi; Editing by John O'Brien)