Ian Hutchinson has been ruled out of the North West 200 after failing to recover from serious leg injuries in time to take his place on the grid.
Hutchinson saw a specialist on Tuesday.
The Yorkshire rider will not have the cage removed from his leg for another couple of weeks as his recovery has been slower than expected.
"We are disappointed that Ian will not be riding but safety obviously comes first," said North West Technical Director Mervyn Whyte.
The Bingley racer will attend next week's event in an ambassadorial role.
The Swan Yamaha racer is continuing his rehabilitation from serious leg injuries sustained at Silverstone last September.
The Bingley man had planned to return to action at this weekend's British Championship round at Croft.
Hutchinson has two North West victories to his name, including one in last year's Supersport 600 race two.
He has also won eight Isle of Man TT Races.