Jenson Button warns Ferrari that Carlos Sainz will give Charles Leclerc “a run for his money”. Button on Ferrari's line-up change.

Scuderia Ferrari team principal Mattia Binotto has been warned he has made a mistake in signing Carlos Sainz if he expects the Spaniard to simply play second fiddle to Charles Leclerc.

Former Formula 1 champion Jenson Button has admitted to feeling “shocked” by Sebastian Vettel’s announcement he is to leave the Scuderia at the end of the season, which opened the door for Sainz’s swift appointment.

Carlos Sainz has proven over the years he is no slouch, with Jenson Button confident that the 25-year-old will give Charles Leclerc a tough time: “If Binotto has gone for Carlos because he thinks he’s a good pair of hands, but won’t give Charles a run for his money, he’s mistaken,” the former world champion said, as reported by Sky Sports F1 – “Carlos is a winner. He’s like his father, he wants to go out there and do the best he can, and he wants to bring home a championship. He’s chosen the wrong person if he just wants a good atmosphere within the team.”

The 2009 title-winner has been left surprised by the timing of the moves, with no driver yet to prove themselves due to the opening 10 races of the campaign either being cancelled or postponed.

That has added to the mystery behind Sebastian Vettel’s early exit. Button said: “It’s just a really weird time at the moment. We’ve not seen a Formula 1 car on track in months, and to make driver choices at a point where drivers haven’t been driving is really unusual. Normally it’s mid-season, you see how the guy is performing during that year, and then you make your decision. Vettel could have been four of five wins in at this point in time, and I’m sure the decision would have been very different. If he was pushed, for me it’s madness. It really is. He is someone you would definitely choose to put in your car if you had an F1 team. There must be more to it. I don’t know if Ferrari is going down the route of not wanting two number one drivers, but it’s a really strange choice for me, and I’m still shocked by the decision of Sebastian not being in a red car.” – he concluded.