Matt Neal faces a race against time to be fit for this weekend's British Touring Car Championship round at Silverstone after breaking a finger during a martial arts training session.
The Honda driver shook down his Civic at MIRA on Thursday and reported minimal ill-effects from the injury to his right hand, but still needs authorisation from a doctor to continue his challenge for the championship.
"I did it a week ago in training, but now it's out in the open," the three-time BTCC champion told AUTOSPORT.
"It's a clean break. Right through the finger below the knuckle.
"It doesn't feel too bad at the moment. It's on my right hand, which I only use to steer. It would have been a lot more problematic on my gear-change hand.
"I've got to go and see a specialist, who is a plastic surgeon, on Friday morning and he'll either give me a 'yes' or a 'no' as to whether I can race or not."
Neal has injured his right hand during each of the past three seasons, but never badly enough to be sidelined from a BTCC round.
"I can't believe that I've done my right hand three years in a row, and each time it's a different part of the same hand," he added.
"In 2011 I broke the hand during a martial arts training session, last year I fell off my motorbike on the way to a session and now this time it's training again. And I'd never hurt that hand before in my life."
Neal lies fourth in the championship, 34 points behind Eurotech Racing's Andrew Jordan and four behind his team-mate Gordon Shedden, who holds second spot.
Honda is likely to clinch both the manufacturers' and teams' championships this weekend.