The Manxman collided with a parked car on stage six and fell heavily on his shoulder - the same one he injured at the Tour de France in 2014.
But while x-rays showed the all-clear, with no broken bones, Cavendish is not able to train and is still in pain from the incident, which could force his withdrawal from the Worlds.
"I'll make a decision [on whether to go to Richmond] on Friday," he said at the launch of the Abu Dhabi Tour. "I had an X-ray which showed it wasn't broken. It wasn't hanging off like last year. But it's worse than I feared."
Mark Cavendish's Specialized Venge
Great Britain's nine-man squad for the road race has already suffered two setbacks, with Team Sky duo Chris Froome and Geraint Thomas withdrawing because if injury and exhaustion respectively.
Thank you for reading 20 articles this month* Join now for unlimited access
Enjoy your first month for just £1 / $1 / €1
*Read 5 free articles per month without a subscription
Join now for unlimited access
Try first month for just £1 / $1 / €1