Danilo Petrucci was not overly concerned by the time sheets at Jerez on Wednesday as he sampled an evolution of Ducati's GP17 for the first time.

After missing the two-day test in Valencia due to family issues, Petrucci spent the day attempting to understand the machine that was a similar spec to what Jorge Lorenzo and Andrea Dovizioso tested last week.

While Petrucci's times didn't catch the eye, the 58 laps he posted around the Andalusian track allowed him to view the machine's potential as "very, very high", with performance in braking and corner exit an improvement on the GP15 he raced in 2016.

"It was the first day," began Petrucci, who ended the day eleventh overall, and the ninth fastest MotoGP machine.

"It was quite good. I use only one new tyre. I didn't use the other new tyre from Michelin and everyone said it was better. I'm quite behind in the classifying but in fact I'm quite happy. I did 30 laps with one tyre and 30 with another.

"My main focus was to try to understand the bike as much as possible with the used tyre, and to try and move something to see if the bike's behaviour change. At the end I go faster and faster in every run. I'm quite happy.

"We have to improve. I still have to find the base from the set-up so I think the rider with the GP16 already have one base. The base is fully evolved. The bike at the end of the season was the best one they got.

"I think the potential of this bike is very, very high. At this moment I don't understand the limit. I don't want to make some extra damages. Tomorrow I will try to use more used tyres and see where the limit is. I want to finish in front of everybody but the target is to exit from the pit with a smile.

"We try some regulations and modifications that were not possible with the GP16. We have to understand this, how is the limit of the front. I felt already that in braking it's already better and also in traction.

"But turning, I still have to understand how to release the brake. Also the feeling in the fast corners is still not OK. I have to work."

Petrucci was sporting a freshly shaved head in Jerez, the result of a bet he had previously placed with friends upon learning that a GP17 was on offer to either him or team-mate Scott Redding.

"It was a good solution," Petrucci said. "The bet was with my friends. They say, 'If you win the bike, you become blonde or bald.' So I realise that if I become blonde I have to cut everything so I jumped directly to the second stage and I cut everything!

"I think if I appear here with blonde hair my team would have fired me because I was absolutely, unbelievably ugly."