Repsol Honda have confirmed that Spaniard Dani Pedrosa will miss this weekend's MotoGP in Assen and will be replaced by Japan's Hiroshi Aoyama.
Pedrosa, 25, broke his collarbone in a crash at Le Mans six weeks ago and has already sat out the last two races.
Aoyama, who normally rides for the satellite Honda Gresini Team, will fill in for Pedrosa, who hopes to fit for next month's Italian Grand Prix.
Test rider Kousuke Akiyoshi will step in to replace Aoyama for this weekend.
During his absence, last season's runner-up Pedrosa has dropped down to fifth in the championship standings on 61 points after six races.
Pedrosa is one of three MotoGP riders currently nursing broken collarbones, with Tech 3 Yamaha duo Colin Edwards and Cal Crutchlow both suffering the injury in the last two races.
Edwards returned from his crash in Catalunya to take third at Silverstone just eight days after surgery, while British rider Crutchlow has travelled to Assen and is hopeful of racing a fortnight after his accident, which forced him to miss his home grand prix.