IndyCar champion Ryan Hunter-Reay will return to IMSA action next weekend at Mid-Ohio when he stands in for Harry Tincknell at Mazda Team Joest.
Andretti Autosport IndyCar driver Hunter-Reay will partner Jonathan Bomarito at the wheel of the #55 Mazda RT-24P for the fourth round of the IMSA SportsCar Championship.
Tincknell is on World Endurance Championship duty at Spa for Ford Chip Ganassi Racing.
The 2012 IndyCar champion and 2014 Indianapolis 500 winner Hunter-Reay last raced DPi machinery last year for the Wayne Taylor Racing Cadillac squad, joining Jordan Taylor and Renger van der Zande for the Daytona 24 Hours, Sebring 12 Hours and Petit Le Mans - winning the latter.
"Mazda has really put a lot into their programme, and Mazda Team Joest have taken a big step up this season," said Hunter-Reay.
"The car is obviously very fast and I'm excited to race it at Mid-Ohio.
"Jonathan is a good friend and we've been team-mates in the past, so it will be great to share the #55 Mazda RT24-P with him and fight for a win.
"I've driven race-winning Daytona Prototypes in IMSA for a long time, the Prototype field is as strong and deep as it has ever been, and I'm thrilled to be a part of it again this season."
Mazda Motorsports boss John Doonan added: "This will be the first time a former Indy 500 champion has been aboard a Mazda at the top level and based on his experience at Mid-Ohio, his experience working with Multimatic previously, and the opportunity he and Jonathan had to drive together a few years back made him a natural fit."
The #77 Mazda will be piloted at Mid-Ohio by the usual line-up of Oliver Jarvis and Tristan Nunez, who scored the squad's best result of the season last time out in Long Beach in fourth place.
Tincknell will return to the #55 line-up in Detroit at the start of June.