Former world champion 
Jenson Button believes new 
Ferrari driver 
Charles Leclerc could force 
Sebastian Vettel into a "tough decision" over his Formula 1 future.
Leclerc is driving for 
Ferrari for the first time in 2019, replacing Vettel's friend 
Kimi Raikkonen.
Vettel ended the 2018 season in disappointing style, with numerous self-inflicted errors causing him to finish in second behind 
Lewis Hamilton, despite being at the top for a large section of the season.
Button has joined 
Sky Sports as a pundit for the 2019 season, and at a promotional day for the channel, he compared the current situation at Ferrari to 
Daniel Ricciardo when he arrived at 
Red Bull five years ago.
"It's a very different atmosphere for Sebastian at Ferrari than it was at Red Bull," Button said to Sky Sports News. "Maybe there's some more pressure. We're going to see how he copes this year. It's going to be a big year for Sebastian. When Daniel came into Red Bull he found it difficult.
"Daniel put him under a lot of pressure and actually outperformed him. I think if Charles can do that this year, it's a tough decision of where Sebastian is going to go for the future and what he's going to do."
Button went onto say that if Vettel's mind isn't in the right place, then his ability is irrelevant.
"If your mind isn't in the right place, then forget it," Button explained. "Charles seems such a happy-go-luck guy, really relaxed, and I think the team are really going to take to him. And that sometimes can hurt the other driver."