The four-time MotoGP race winner suffered a broken shoulder blade after Luca Marini collided with him in the sprint race at the Portuguese GP in March.
Though Bastianini didn’t require surgery on the injury, it forced him to miss the Argentina GP the week after Portugal and the third round in America.
Bastianini completed a private test on a Ducati superbike on Tuesday prior to the Spanish GP and was cleared on Thursday by MotoGP doctors at Jerez to take part this weekend.
The Italian was 20th on the combined standings after Friday’s running and admitted then that he was “in a lot of pain” and was unsure if he could continue on Saturday.
Ducati has now confirmed Bastianini will withdraw from the remainder of the Spanish GP.
“He said it was too painful,” Ducati boss Davide Tardozzi told MotoGP’s world feed.
“After a couple of laps it’s too hard to ride. So, we don’t want to take the risk, so we decided to stop.”
Bastianini’s continued absence means he will not have completed a grand prix since last November’s finale in Valencia.
Due to the additions of wildcard Stefan Bradl for Honda and KTM’s Dani Pedrosa, the grid remains at 22 riders despite three full-time runners not participating.
Eight-time world champion Marc Marquez was forced to miss the Spanish GP after doctors advised him to let the broken thumb he suffered in the Portuguese GP heal more.
On Thursday at Jerez, Marquez told the assembled media that he was told by doctors that he risked ending his career if he injured his hand again.
Tech3’s Pol Espargaro continues his recovery from multiple fractures following his violent crash during FP2 for the Portuguese GP last month.
No timeline has been given for Espargaro’s return, but both Bastianini and Marquez are expected to return for the French GP in two weeks’ time.
Qualiyfing for the 2023 Spanish GP gets underway at 10:50am local time.
