Maverick Vinales has made a major change on his side of the Monster Yamaha pits by splitting from crew chief Esteban Garcia ahead of this weekend's Catalunya MotoGP.

Vinales has been absent from the podium ever since victory in the Qatar season-opener, causing him to slip from first to sixth in the world championship, 41 points behind team-mate Fabio Quartararo.

Monster Yamaha team director Massimo Meregall said the Vinales-Garcia split was a mutual decision

"Esteban joined our team in 2019. He and Maverick had already worked together before in 2013 and won the Moto3 World Championship that year," Meregall said.

"We are very grateful to Esteban for his dedication and passion during our time spent together, which led to eleven podiums for Maverick, including four wins, three second places, and four third places.

"Saying ’Goodbye‘ to one of our crew members is always a sad occasion, but it was a mutual decision based on what‘s best for both parties. We wish Esteban all the best for the future."

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After winning his first MotoGP race with Suzuki, Vinales arrived at Yamaha in 2017, where he was paired with Jorge Lorenzo's title-winning crew chief Ramon Forcada.

Despite victories in three of their opening five races together, success suddenly dried up and tensions grew in the Vinales-Forcada partnership. By the time a fourth win was added, at Phillip Island in 2018, the decision had already been made to part ways for the following season.

While Forcada joined Wilco Zeelenberg in switching to the new Petronas Yamaha squad, working with Franco Morbidelli, Garcia - who had been at Vinales' side during his title-winning 2013 Moto3 campaign - was drafted in to the factory team.

The pair have taken four wins together and, although unable to mount a season-long title challenge, Vinales was the leading Yamaha rider in the 2019 world championship.

But that all changed in 2020, when Morbidelli (and Forcada) finished title runner-up, Quartararo also matched his Petronas team-mate with three wins, while Vinales managed just a single victory and sixth overall.

With Quartararo making a stunning start to his career at the factory team, Vinales faces being beaten by a team-mate for the first time since Valentino Rossi in 2018.

Called in as Garcia's mid-season replacement is Silvano Galbusera, who took over from Jeremy Burgess as Rossi's crew chief in 2014. Rossi and Galbusera won nine races together and fought for the 2015 title until the final round, before Galbusera was replaced by David Munoz for 2020.

Galbusera then switched to crew chief duties for the Yamaha Test Team, with Jorge Lorenzo and now Cal Crutchlow, but was seen in the factory team garage at last weekend's Mugello round.

Speaking after a disappointing eighth place in that race, Vinales questioned the decision to move away from the soft front tyre but otherwise gave no indication of the crew-chief change to come.

"I really thought the result would be totally different because Mugello is a track I like and feel good at, but somehow after FP1 I lost the feeling," Vinales said.

"The only thing I changed from FP1 to FP2 was the front tyre. I just went to the medium, and then the problems started. So I don't know why we didn't try the soft front. I think we didn't pay enough attention to that, because in FP1 I felt fantastic, I did 1'47.1 in just six laps.

"So we need to check, we need to analyse. In one way it's difficult, because we made a bad result, but in the other way it's positive, because we have data from FP1 to understand why.

"We have one guy in our team [Quartararo] who is winning, and we have his data also, so we need to analyse and keep working."