Leh Keen has been released by WeatherTech Racing, effective immediately, with Porsche Junior Sven Mueller having been tabbed to drive the No. 22 Alex Job Racing Porsche 911 GT3 R in this weekend’s Continental Tire Road Race Showcase at Road America.

Mueller, the Porsche Mobil 1 Supercup championship leader, will join Cooper MacNeil at the wheel of the GTD class contender for the WeatherTech SportsCar Championship round, the team confirmed Thursday.

Keen and MacNeil had been one of the longest-running driver combinations in IMSA competition, with 38 total starts together, dating back to 2012.

“We decided to make a driver change for the rest of the season in the WeatherTech Porsche,” team owner Alex Job said. “Leh Keen has won races with us, but off the track circumstances led to a change. We wish Leh all the best going forward.

“Sven is a fast young driver that is currently leading both the Supercup and Carrera Cup series in Europe.

“We are looking forward to having a successful weekend of racing at Road America. We will reassess where we are with the 22 Porsche after this weekend.”

The 24-year-old German, who was originally en route to Road America to drive the No. 540 Black Swan Racing Porsche, which has been withdrawn, will make his second career WeatherTech Championship start after driving for Frikadelli Racing at Daytona.

Mueller has claimed three wins in six starts in Supercup this year, with 10 wins out of 12 starts in Porsche Carrera Cup Germany.

“It is going to be a real pleasure to drive with Alex Job Racing,” Mueller said. “I already know Mario Farnbacher and Alex Riberas from racing in Europe.

“To have a good strong teammate like Cooper makes this weekend even more interesting. I have been learning the Road America circuit on the simulator and I am looking forward to driving it tomorrow.”

Alex Job expands into a three-car operation this weekend, with the addition of the No. 77 WeatherTech Porsche for Gunnar Jeannette and David MacNeil, which is expected to be a one-off entry.