Ben Spies, absent from this weekend's Spanish MotoGP, is to undergo further medical checks on his healing shoulder.
The former WSBK champion and MotoGP race winner, who underwent major shoulder surgery after an accident in last October's Malaysian Grand Prix and suffered related muscle problems in Austin, is aiming to return for the French round later this month.
However the wording of the Pramac statement suggests this will depend on the outcome of the latest tests.
"On Monday, 6 May, Ben Spies will undergo further medical checks on his physical condition following the problem with a pectoral muscle he suffered during the warm-up session at the Austin GP," said the team statement.
"Only after these checks and subsequent diagnosis have been carried out will it be possible to have a clearer indication regarding the Texan rider's imminent return to the championship.
"The Ignite Pramac Racing Team rider is now spending five days a week doing three or more hours in rehab and an additional two hours of cardio work. His pectoral muscle is still less than perfect, but it is already possible to see some improvement in rotation and movement."