Simon Trummer will return to the GP2 series in Austria after securing a seat with the Hilmer Motorsport team.
The Swiss driver competed in the series with Rapax in 2014, before joining the ByKolles team in the World Endurance Championship this year.
But the 26-year-old will be back in GP2 this weekend at the Red Bull Ring, racing the car driven by Johnny Cecotto Jr. in the previous two races in Monaco and Barcelona.
"I am very happy to be back in a GP2 car, and especially to be part of Franz Hilmer's team," he said.
"I have great respect for Franz and for what he has achieved so far and I would like to thank Franz for this opportunity.
"I know the track in Austria but I have no experience with the new DRS on the GP2 car. But I am sure that I will adapt and be up to speed quickly. I can't wait to race again on Saturday."