Multiple grand prix world champion Max Biaggi will test a Pramac Ducati MotoGP bike at Mugello this week.
The 41-year-old Italian announced his retirement from the sport in November last year, having just clinched a second World Superbike crown.
He won four consecutive 250cc world titles between 1994-97 on Aprilia and Honda machinery.
He won 13 times and finished runner-up on three occasions following his graduation to the premier class.
Biaggi will test the Pramac Desmosedici over a two-day run on Thursday and Friday of this week.
A Pramac statement said the team had planned to run Spies at Mugello, but as a result of his injuries "therefore decided to let Max try the Texan's bike, which had already been prepared for the test."
Ducati test rider Michele Pirro will substitute for Spies at the forthcoming Barcelona race.