Max Biaggi is to make a surprise return to riding a MotoGP machine. The former 250 and World Superbike champion will take a seat on Ben Spies' Ignite Pramac Ducati as part of a one-day test at Mugello, as part of Ducati's testing program, according to Italian site GPOne.com.

Spies was scheduled to stay on at Mugello to take part in a two-day test, but after the first day of practice at last weekend's Italian Grand Prix, it was clear to both Spies and Ducati that his shoulder was still too weak to ride a MotoGP machine. With work continuing on the Desmosedici, it was important for Ducati to get as much data as possible on their bike, and so Biaggi was offered the chance to ride the machine.

The test, Ducati team boss Paolo Ciabatti told GPOne.com, is just an opportunity for Biaggi to enjoy himself, and to provide some feedback on the bike. Not much is expected of it, as Biaggi has not ridden a MotoGP machine since 2005, when an ill-tempered split with Honda saw him forced to leave the MotoGP paddock. Biaggi has never ridden a Bridgestone MotoGP tire which, though much improved, are still tricky to learn. And electronic controls have come on in leaps and bounds since then, though the electronics Biaggi used at the factory Aprilia team in World Superbikes last year were at a standard very close to MotoGP.

Biaggi will join factory riders Nicky Hayden and Andrea Dovizioso on track on Thursday, with the factory men due to stay on for another day after that. Up for testing will be the latest iteration of the lab bike, which features further improvements over the Desmosedici GP13, mainly in the area of chassis stiffness. When MotoMatters.com asked team coordinator Vitto Guareschi when the race version of the lab bike would make its debut at a race, Guareschi replied that no decision had been made yet. "When we know the new bike is ready, we will race it," he said. The lesson had been learned in the past two years, when Ducati had rushed to introduce too many new parts at race weekends without thoroughly testing them beforehand. "In the past, we introduced too many things, now we wait until it's ready," Guareschi explained.

Biaggi's test does not mean that he is a candidate to replace the injured Ben Spies in the upcoming races, Ciabatti told GPOne.com. For the Barcelona race, Michele Pirro will step in for Spies once again, though this time, he will ride with the lab bike, rather than Spies' standard GP13. The engine of the lab bike has the same basic dimensions as the standard GP13, and so Pirro will be able to use the lab bike without disrupting Spies' engine allocation. Ducati had been hesitant to have Pirro race on the standard bike, as Pirro is such a crucial part of Ducati's testing plan, and their MotoGP project, Vitto Guareschi told MotoMatters.com on Sunday. They feared that the project could suffer severe delays if Pirro was injured in a crash.