Sauber F1 drivers 'not best buddies' after rivalry in GP2

The duo were rivals in GP2 during the 2012 and 2013 seasons before being paired together at Sauber for 2015, where both will remain this year.

Ericsson said he was unsure how the two would get on together but he believes they have developed a good working relationship.

"Going into this season it was into the unknown because me and Felipe had a bit of a history in GP2," Ericsson told Autosport.

"We had some tough battles and we were maybe not best friends there but to be honest, we've been working well together.

"We're not best buddies, but I don't think there is any reason to be that as team-mates.

"But what we do well is that we can discuss things and we usually do that for every session.

"That is important especially in a small team where we don't have the resources to throw things on the car."

Ericsson and Nasr collided in the United States Grand Prix at Austin but they sat down and cleared the air afterwards.

"In Austin, we had a bit of a disagreement there but after the race we had a chat about it and then we moved on and it was 100 per cent fine," he said.

"That is a strength, too. I'm happy he is staying and we can continue working together next year."