Catalan Grand Prix winner Fabio Di Giannantonio has withdrawn from MotoGP's post-race test at Barcelona following his involvement in Alex Marquez's horrific crash.

Di Giannantonio's VR46 Ducati was taken down by flying debris as Marquez's Gresini Ducati cartwheeled down the back straight and disintegrated having clipped Pedro Acosta's suddenly slowing KTM.

An entire wheel assembly and front fork struck Di Giannantonio, leaving him with an injury to his left hand.

He still elected to take both the subsequent restarts despite the pain he was in, and battled to the second grand prix victory of his career.

But his VR46 team said ahead of the Monday test starting that Di Giannantonio had withdrawn to "focus on recovery".

The next race is at Mugello in a fortnight.

Marquez sustained neck and collarbone fractures in the crash, with Johann Zarco suffering leg injuries in his subsequent massive accident at the next restart.

VR46 team-mate Franco Morbidelli said the discomfort Di Giannantonio was in should not be underestimated.

"Diggia did incredible work because he was screaming a lot from one start to the other so I thought he was in big pain," said Morbidelli.

"When he was able to win the race, I was impressed."