Muggeridge suffered a highside and hit his left knee on the footpeg of his CBR600 machine.

"I did well to save the crash but in doing so really banged my knee," Muggeridge explained. "I think I've damaged the cartilage or at least the ligament.

"I'll see the doctor this afternoon and see what he says but there's quite a bit of pain there and I'm not sure if I'll be able to continue tomorrow."

Muggeridge's team-mate Michael Laverty was 24th fastest and the young Irishman was happy with his first day's performance.

Laverty said: "It's my first time at Imola and first time on Pirelli's Supersport tyres. I managed to get about three seconds off my time of this morning. I just missed out on a faster lap at the end of this afternoon's session but that was no drama, we've got tomorrow."