“I’ve been through this situation before,” former world champion Jenson Button told Sky. “I wanted to leave my team for another team. I have made mistakes in my career. I was a few years into my F1 career when I made this mistake.
“The CRB decided against me moving so I stayed with BAR.
“For Oscar it is different.
“He hasn’t even raced in an F1 car. Alpine has funded his development and now he’s like: ‘You know what? I’ll go to them because they are better for my career!’
“He has got to look after No 1. But you can’t make enemies this early in your career.”
Another ex-F1 champion, Nico Rosberg, added on Sky: “Alpine really did such a bad job. It is unbelievable for such a high-profile team to manage it so badly.
“They invested millions into Piastri’s career but didn’t have him locked into a contract, so he could go away and take an offer from McLaren.
“That’s really, really tough.
“Piastri’s manager Mark Webber? Great job. They got him a fantastic race seat at McLaren. That’s huge.
“Nevertheless it will be tough for Oscar to do well there because Lando is world-class. He is world championship material.
“It won’t be easy for Oscar to come in and to straight away do better than Daniel Ricciardo.”