Robin Frijns has been forced to sit out this weekend’s Blancpain GT Series Endurance Cup opener at Monza with a knee injury, and will be replaced by Markus Winkelhock.

The Dutchman posted on social media on Thursday explaining that his right knee “collapsed” while running, resulting in a cut ligament.

Frijns will therefore be replaced by Winkelhock in the No. 17 Audi R8 LMS this weekend. The 36-year-old German joins Stuart Leonard and Jake Dennis in one of the four Belgian Audi Club Team WRT cars.

While he will miss this weekend’s three-hour Endurance Cup race at Monza, Frijns is hopeful to be back in the car in two weeks’ time for the Sprint Cup round at Brands Hatch.