Jorge Lorenzo reckons Ducati is behind its rival manufacturers in terms of developing its bike for the 2018 MotoGP season.
Ducati was focusing on minor changes during the two-day Valencia MotoGP post-season test, while Honda tried 2018 prototype engine and chassis and Yamaha also trialled a new engine.
Lorenzo says that means "maybe we are a little bit more delayed than the others" and Ducati will not be at that level until the Sepang test at the start of 2018.
"They tried new engines, new chassis this time," said Lorenzo. "Honda especially looks like they improved a little bit, and we still don't have something new, brand new.
"It is because the engineers, for some reason, have this little delay.
"Probably we will have to take benefit of that at Sepang - something will probably arrive in Sepang."
Lorenzo said the small updates that were evaluated at Valencia did not make the bike stronger.
"The semi-new bike, for the moment, doesn't work better than the actual [current] one," Lorenzo added.
"[On Wednesday] we tried many things [but] more or less we confirmed the same pieces.
"We didn't find anything particularly better, but it was important to try to be sure how everything [works]."
Lorenzo's team-mate Andrea Dovizioso said Ducati used the test more to decide the direction of the 2018 bike, rather than bring any major updates, having ended his final day of running early.
"We tried small things, unfortunately we didn't have the '18 bike here to really start the season," said Dovizioso.
"We just wanted to try different things to decide in which way it will be the '18 bike."