Iannone is still recovering from the back injury he suffered during practice for the San Marino Grand Prix. Michele Pirro, the Borgo Panigale manufacturer's test rider, replaced him both at Misano and Aragon.

However, Pirro will be running in Valencia from Wednesday to Friday, in all likelihood with the base for next year's Desmosedici, a circumstance which has meant he was unable to replace Iannone in Japan.

Given the circumstances, Ducati decided to offer Stoner the chance to race.

"We gave him the chance, but he said no," Paolo Ciabatti told corsedimoto.com.

As such, Andrea Dovizioso will be the only works Ducati rider racing this weekend at Motegi as the Italian team waits to see the evolution of the microfracture Iannone suffered in his T3 vertebra.

The week after Motegi, the championship arrives at Phillip Island, Stoner's home circuit.

"First we have to wait and see if Andrea recovers, and then we'll see what we do if he doesn't. Initially Casey had no intention to return to the paddock until the final race in Valencia.

"But maybe since it's Australia he will change his mind, I don't know," Ciabatti said.

During the summer, the Italian manufacturer admitted to the possibility that the Aussie rider could return to racing as a one-off, with a wildcard entry, something Stoner ruled out after a test together with most of the field in Austria.