Jonathan Rea is set to make his MotoGP debut as Casey Stoner's Honda stand-in for the Misano and Aragon races.
The 25-year-old World Superbike racer, who is currently fifth in the WSBK standings with the Ten Kate Honda team, will test the works Honda MotoGP bike at Brno on Monday and again at Aragon on 4-5 September.
A Honda team statement said that "doctors anticipate" that Stoner will have to skip the next two MotoGP rounds. Rea will therefore replace him.
Neither Misano nor Aragon clashes with this year's WSBK calendar.
The Briton already has some MotoGP testing experience but has never raced in the series.
Honda's remaining works MotoGP rider Dani Pedrosa is now within 13 points of championship leader Jorge Lorenzo after winning in the Czech Republic this weekend.