Since winni💜ng on its MotoGP🐈 debut in Qatar, Ducati's GP18 has come under threat from the previous 2017 model in Argentina and Austin.

Pramac's Jack Miller was the top Ducati rider in Argentina, when Avintia's Tito Rabat finished right on the rear wheel of fa🌺ctory star Andrea Dovizioso.

While the Italian then restored orde𓃲r with a fifth place in Austin, Miller and Rabat♎ again beat the other GP18s of Jorge Lorenzo and Danilo Petrucci.

At Jer♊ez on Thursday, Miller's GP18 team-mate Petrucci was asked to explain the situation.

Whilst ruling out a repeat of the back-to-back comparison with the GP17 conducted by Lorenzo at the T𓃲hailand test, the Italian confirmed that the last two races have created some doubt.

"Maybe Jorge at that time was not s🌺o sure about his bike but for me in Sepang, Thailand and Qatar the GP18 was better," Petrucci said. "Now in the last two races for sure we have thꦕis doubt at the moment."

Casting his mind back to the sꦜtart of pre-season testing, Petru🔯cci added:

"After the fiဣrst test in Sepang we said 'okay [the GP18 and GP17] are very similar'. Maybe with the GP17 you have to ride for two or three laps to make a good lap time. During testing with the GP18 on the first or second lap you already found the right feeling.

"Then in Argentina we started to hꩲave som𒈔e problems and we found the GP17 more competitive.

"Both Miller and Rabat were competitive in Argen🌠tina🧜, maybe more than me and Dovizioso. For sure Jack did a great weekend in Argentina but even Tito was pushing Dovi until the last corner.

"For me Austin was a disaster race but we saw that with th⛎e GP18 we change a lot of things, we struggled to find the good set-up. With the GP17 they know the set-up and they know prett𓃲y well the bike, because it's the bike from last year with all the data.

"Like every year, with a new bike at the beginning of the season you need to improve, to develop. Hopefully things can change herಌe but I don’t know sincerely. We'll see. I hope the bike makes a small step at this race."

Pe𝓡trucci has more knowledge of the new Jerez asphalt than most having taken part in private tests at 🎃the track in both November and March.

"In November 𝔍the situation was better, like always in November we don't know why but since many years November is the fastest montꦓh at Jerez where we can set the record. I remember Lorenzo was very fast in November.

"But I tested here after Qatar and the situation was a little bit worse. Especially in Turn 1 and Turn 8 the [new] asphalt is not so perfect. I mean there are many patches. I don't know why because in the other parts of the track the asphalt is very good. Lot of traction. And for sure is 100% better compared to the old asphaཧlt. But in Turn 1 and 8 you have to be quite careful.

"Anyway, this extra gr✃ip is only better for us. We st🌱ruggle a lot when the compound of the tyre is harder, for example in Austin and Argentina.

"Here during the test we changed the bike a✤ lot and I think we will start with th🌟e winglets from the first session tomorrow. So I think [doing the tests means] I have an advantage compared to the other Ducati riders.

"Anyway I'm not happy about the resul🥂t in Austin so I want to💝 improve. In Argentina I was quite fast during the race but I started in 18th. I did a great comeback to 8th but it was not a great race.

"In Austin I fought very ha𒈔rd on Saturday to stay in the top ten, but then in the race I struggled a lot with the hard tyr🥃e and I was absolutely not competitive.

"I crossed the🎶 finish line at the end of the first lap in 17th but I was not able to be fast all the race. I don't know why. I maybe have some ideas."

From what he's seen at the private tests, the Repsol Hond🍎as will start as the team to beat this weekend.

"For sure here in Jerez I don't think we have the same speed likeꦇ in Thailand and Qatar.

"I mean, we've been testing here for two days with Marquez and Pedr﷽osa and they were quite fast. Faste𒊎r than us! So we have to work. For sure Honda made a big step ahead and we'll see.

"I lost many points in Austin. After Qatar I was fighting for a top five in the championship and now I'm tenth, so I want to improve on my performance last 🙈year. I have more points than last year but every year it's a different story.

"But I'm quite focussed and I want to use this extra test here to maybe st💛art a step ahead.⭕"