In the six rounds so far this season, Espargaro has qualified an average of sixth, including three front row starts and pole position in Argentina.

By contrast, Vinales has been an average of just 14th on the grid, starting inside the top twelve on only one occasion - fifth in Argentina - where he took his best Aprilia finish of seventh in the race won by Espargaro.

A nine-time MotoGP winner on Suzuki and Yamaha machinery, Vinales isn’t able to find the same step in performance as Espargaro on brand-new rubber.

At Jerez, the qualifying problem was magnified by an issue with Vinales’ front holeshot system, leaving him 22nd at the end of the opening lap.

In a race that saw Espargaro take his fourth podium since Silverstone 2021, moving Aprilia out of concessions, Vinales could only fight his way to 14th place.

“It's what I always spoke about, starting 12th is hard and then we had a problem with the front [holeshot] device and I was not able to engage it. I did such a bad start. A lot of wheelie,” he said.

“But the [real] problem is we cannot do one fast lap in qualifying. So then we need to keep pushing through all the race to recover, which means the tyre [temperature] goes up, the pressure goes up and then everything is not working.”

The issue Vinales and Aprilia are trying to solve is how best to adjust the RS-GP in response to the change in rear grip provided by brand new rubber during a time attack.

“For the pace, we are just one tenth off, but in the fast lap we are +0.7,” Vinales said after qualifying at Jerez. “The difference is too high.”

Vinales: At Yamaha it was two steps on the front preload

As an example of the kind of ‘details’ needed to tune a MotoGP bike for a time attack, Vinales recalled what eventually worked best at Yamaha, where he took 32 front row starts from 2017 to mid-2021:

“At Yamaha, I was always adding two steps on the front preload just to not stress the front tyre with the extra rear grip, because you can brake a bit deeper or whatever,” Vinales explained.

“We need to find these kind of details, but we’ve only had five races [until Jerez] and it took four years [at Yamaha]. So we need to work very quick. The others have 5-6 years with the same bike, but we can do it.

“I think it’s a matter of understanding what you need, especially from the electronics side and also the setting side.”

Part of the reason it’s taking time to find those small changes is that, while logic would suggest an increase in rear grip with a new soft rear tyre, the lack of a clear base setting means Vinales sometimes experiences the opposite effect.

“It’s very difficult to turn when I put a new tyre, but it’s not because I have a lot of [rear] grip, I don’t have a lot of grip, because when I open the gas there is low grip.

“Then when we lose traction, I push the front, overheat the front and I'm not able to corner.

“For me it’s to do with the setting and how the bike has been for years. With used tyres you have a good feeling, but when you put new tyres and have to make the difference, it’s like hitting a wall.”

Espargaro’s qualifying form proves the RS-GP can work extremely well over one lap and Vinales is trying to learn from his fellow Spaniard’s technique. However, there is now a clear difference between their bike set-ups.

“All the time we go closer to Aleix’s riding style because I think with this bike it’s what pays off. But it’s not what I’m looking for [in the long term] to feel natural on the bike,” Vinales said.

“If you compare Aleix’s bike and my bike [set-up], it’s like sun and moon, totally different. But we need to think that this bike is building up with a very different riding style, so we need to find a good compromise.

“I think we have a bit too much weight in the front. But [Portimao], where the grip was very high, brought us to that position. Now [at Jerez], without as much grip, we have doubts if this setting is good.

“Obviously, we don't have a base set up. We are working very hard. We made a gamble for the race. We put even more front weight. It didn't work. But it gave us information to see what we have to do.

“Step by step we are understanding. It’s a pity because I have a good opportunity in front of me which I'm not able to take at the moment and also the way we finished the weekend is very frustrating because we started really well.

“We need to work on the setting, especially on the weight balance, because the way I ride the bike is totally different. So we need to be very focused on how we are on entry, mid and exit of the corner, with the weight of the bike.

"Because I don't feel grip from the tyres and we need to see why.”

Vinales continued his quest for a better set-up and one-lap pace during the Jerez post-race test, where he set the 16th best lap time, 0.3s behind Espargaro in seventh.

“Probably all the morning and middle of the afternoon we want to spend on hard tyres and then we want to put two or three soft tyres in a row to see the different settings. We need to try. We don't give up.”

Maverick Vinales: ‘I don’t stop. I’m obsessed!’

Vinales, who like most of the grid is yet to sign for 2023, insists succeeding with Aprilia is constantly on his mind, even away from the race track.

“I don’t stop. I’m obsessed! I don’t stop thinking how to improve,” he said. “At home I watch the races a lot of times, the practices, looking at how to improve.

“The only thing I see, through all our weekends, is that we don’t get the maximum in the time attack.

“But it’s a matter of time. The day will come when we will succeed and will be at one with the bike.

“There are people with a lot of experience of their bikes, many years. I’m not patient, I’m normally very explosive, but in this case I’m learning to be patient! It’s not easy because everything is so tight. Three tenths off and you are 20th.”

Qualifying nearer the front would not only make Vinales’ life easier from a tyre performance point of view.

“In my mentality, when I’m front row or somewhere like that I feel much more calm than if I’m starting 14th. I feel more at home when I’m in the front. I don’t want to lose that!”

Vinales brushed aside questions about next season, saying only that his priority is to be in a position where he can deliver at his maximum for a full MotoGP season.

“I don’t decide [yet],” he said. “I would like to take out all I have in one season to see what I’m able to do. I tried [in the past] but I could not do it. I want to do it. I don’t want to stop without doing it.”

Vinales starts this weekend’s Le Mans round 14th in the world championship, with Espargaro in second place behind Fabio Quartararo.

Franco Morbidelli, who took over Vinales' seat at Monster Yamaha, is 16th.