Bussei injured his right hand in a Supermoto accident three weeks' ago and initially turned down the chance to ride at Monza as a result. However, with AMA star Jake Zemke unable to take the seat, and after a medical check, Bussei decided to try and compete.
The 35-year-old former Italian Superbike champion was 27th out of the 29 riders by the end of second qualifying, but has reluctantly withdrawn from Sunday's races due to pain from his right hand.
"I'm really sorry but my physical condition won't allow me to ride the bike," he said. "I'm in a lot of pain after only few laps and it is very dangerous to race in these conditions. I spoke with my team and we decided that is better not to start in tomorrow' races.
"It's a difficult decision for me because today was not so bad for us and I feel better on the bike and I'd like to thank all of my technicians for their great job here in Monza," he added.
