Peter Hickman will miss this morning's Bennetts British Superbike warm-up and potentially the races after being taken to hospital overnight.
Hickman, who led the way on the opening day of action at Thuxton, struggled to find the pace on Saturday after waking up feeling unwell.
Qualifying 11th for today’s opening race, the Lincolnshireman was taken ill in the paddock in the evening and taken to Winchester hospital by ambulance.
He is currently being kept in for further scans and treatment and will miss this morning's warm-up, but he is hoping to be back for the races.
UPDATE 11:18: While Hickman missed warm-up, he is on his way back to the circuit and plans to race.