Nicky Hayden says he will not be able to judge if he is fit to compete at Misano this weekend until he gets some dry running.
The American was one of the few factory riders to take to the track on Friday as rain showers, cold temperatures and strong winds blighted the opening day of MotoGP's San Marino Grand Prix.
Hayden completed five laps in the morning, having missed the Czech GP due to the hand injuries he sustained in his Indianapolis qualifying crash.
He was pleased with his physical condition, but acknowledged that the tentative laps in the wet told him little.
"I went out a little bit in the damp this morning with a wet set-up, just to check the bike," said Hayden.
"I cruised a couple of laps and my hand wasn't too bad in those conditions, but we were all obviously way off the pace."
The Ducati rider wants to wait until he has evaluated his fitness on a dry track before confirming whether he will ride this weekend.
"I really won't know more until I get out in the dry and see if it's even going to be possible to race," said Hayden.
"I don't have much strength, and although it was fine for light braking, it could be a different story in the dry.
"I wouldn't mind more rain, but I wouldn't want to go into the race with no dry track time."