MotoGP champion Casey Stoner felt there was little that could be achieved in Friday practice at Valencia due to both the rain and what several riders felt was a poor track surface.
Stoner was quickest overall thanks to a late lap in morning practice, but took little satisfaction from the result.
"It hasn't been a great day to be honest, we've never had a great feeling here in the wet," he said. "I love riding this circuit in the dry, but there seems to be some sort of oil or grease on the circuit. I'm not sure if it's due to a lot of car rubber down but it makes things hard for sure.
"It's been pretty useless in terms of finding a good set-up. Both sessions began with a little water and then drying out toward the end. When it's like this you're chasing the set-up all day so we didn't do too much work on the bike.
"We tried a few small things to make it better in the wet, but then as it dried up we saw everything we had done was a waste of time. We'll wait and see what tomorrow brings and if it does rain again I hope it at least rains consistently so we can get a full wet session in."
His teammate Dani Pedrosa agreed that the circuit was not in great shape.
"The track surface is quite old and very slippery, even when the track was drier it was still tough," said the Spaniard.
Pedrosa was content with his second-fastest time in the morning, but was only ninth in the afternoon.
"This morning we had a very good run, but in the afternoon we had some issues on the bike with the rear shock and I only managed a few laps, spending a lot of time in the garage making changes," Pedrosa explained.
"The feelings are not so bad and I think we need to be ready for mixed weather conditions, improving the setup step by step. Let's wait and see if tomorrow we have some dry sessions to get out on slick tires, this would be important to better understand the direction to take on the set-up of the bike."