Vettel not good at handling F1 pressure - Berger

Vettel made an inauspicious start to life as an Aston Martin driver in Bahrain last weekend, the German classified 15th after being penalised for a late-race collision with Esteban Ocon's Alpine.

That was after he started the race from the back of the field, a Q1 exit compounded by a five-place grid penalty for a yellow flag infringement.

The disappointing showing added to an ongoing run of poor form for the four-time world champion, who spent the past two seasons in the shadow of teammate Charles Leclerc at Ferrari.

According to 10-time grand prix winner Berger the issue for Vettel is pressure, the German at his best when he's in a clear team leader role and not being pushed by the other side of there garage.

"Sebastian is a four-time world champion so he's one of the outstanding drivers, no question," Berger told the In the Fast Lane podcast.

"But he never reacted well under pressure. Remember when Daniel [Ricciardo] came to Red Bull [he] was very strong and he put pressure on Sebastian. For Sebastian it was difficult to cope with it. In Ferrari it was the same thing.

"I just feel when you watch him, you feel he's not free. He's not relaxed enough. He's trying to prove things that, at this moment, aren't possible because the car isn't good enough or his own form isn't good enough.

"When you're in this situation you need to sit down, take a step back and say 'well, take it easy and the success is going to come again'.

"In saying that he's at the end of his career too. When you've done so many races, when you're already a four-time world champion, then comes a point when maybe you're not in a situation where you want to take all the risks, where you fight like you would fight before you won any races.

"In some way it just doesn't work out well for him. He starts to make mistakes and people start to question him. That's just step-by-step more pressure, and, as I said at the beginning, he doesn't like pressure."

Vettel is facing a unique teammate dynamic at Aston Martin given Lance Stroll's father Lawrence Stroll is a part-owner of the team.

But Berger doesn't think that will be an issue for Vettel if he can start out-performing Stroll, the team still likely to focus its attention on the faster driver regardless of family ties.

"It depends on his performance," added Berger.

"If you're slower than your teammate, and your teammate is also the owner of the team, things will maybe turn more there. But is it not everywhere the same? If you're slower than your teammate, teams will naturally concentrate more on the one that is faster.

"At the end of the day it's more psychological. It's just an uncomfortable situation when you're in a team and your teammate is faster.

"But that's something you have to deal with. If you're a sportsman at this level you have to deal with strong teammates. '

"And I have to say Lance isn't doing a bad job at all. He's performing. The only thing at the moment, I think he is struggling with the rear end of the car. The car doesn't look that good.

"I think it's not really a driver issue they have at the moment, the car isn't performing the way [Aston Martin] were expecting."