Nathanaël Berthon, Rodolfo Gonzalez and Karun Chandhok were initially announced to race in the Four Hours of Red Bull Ring, but the Irish team has now decided to skip the event.
Berthon, who was recently added to the Caterham F1 Development Driver Program, was already set to miss the event, due to a clash with the GP2 Series round at Hockenheim.
Murphy Prototypes is expected to return to the series for the final rounds of the season. Greg Murphy’s team will also provide support for Eurasia Motorsport in the Asian Le Mans Series this weekend.