Ben Spies has been forced to abandon his MotoGP return after suffering another shoulder injury, at Indianapolis on Saturday.
The Pramac Ducati rider has only raced twice this season due to right shoulder injuries - plus associated surgery and muscle problems - from last October's Malaysian race.
13th in Friday practice at Indianapolis, but finally happy with his right shoulder, the Texan was then thrown over the front of his Desmosedici at turn four during the Saturday morning session, landing heavily on his left shoulder.
The former WSBK champion and MotoGP race winner shunned the offer of a stretcher, but was unable to remove his helmet without assistance and duly pointed to his left shoulder.
Pramac has now confirmed that Spies suffered: "A 2nd-3rd degree dislocation of the acromioclavicular joint in his left shoulder.
"Fortunately, Spies' right shoulder, which recently underwent a long rehabilitation process, wasn't injured in the fall.
"On Monday, the Texan will undergo additional, more thorough exams, after which it will be possible to better understand the necessary recovery time."
Adding to Spies' misery, there is little time to heal without missing more races, with the Brno and then Silverstone rounds taking place in the next two weekends.
Rookie team-mate Andrea Iannone missed July's Laguna Seca round due to a dislocated shoulder at the previous German event - and is still struggling with the injury this weekend.