MotoGP returnee Hiroshi Aoyama has sustained a fractured wrist in a motocross accident.
The 31-year-old Japanese rider fell while training on a motocross bike at a Barcelona track last Friday.
Aoyama will not require surgery and has been ordered to rest prior to the first MotoGP test of 2013 at Sepang on February 5-7, which he is expected to be fit for.
The 2009 250cc world champion switched to World Superbikes last year after losing his Gresini Honda MotoGP seat at the end of 2011.
But he made his comeback to stand in for the injured Yonny Hernandez on Avintia's CRT bike at the Valencia season finale, and also secured a 2013 seat with the squad.