London, Aug 17 (IANS): Champions Chelsea's striker Diego Costa on Monday urged his teammates to keep a "cool head" despite their early season woes in the English Premier League (EPL).

The defending champions lost 0-3 to Manchester City on Sunday and they drew 2-2 against Swansea City on August 8 to leave them without a win from their two opening games for the first time in 16 years.

"We need to improve right now, we need to do things better. But we need to keep a cool head and communicate better. The coach did the pre-season just as he needed to, our fitness is fine, we just need to win a game and everything will change," Costa was quoted as saying by dailymail.co.uk on MOnday.

It's been a turbulent start to Chelsea's season with team doctors Eva Carneiro and Jon Fearn removed from the technical staff from game days after upsetting coach Jose Mourinho.

Captain John Terry was substituted at half-time for the first time under the manager's reign on Sunday when the team was down 0-1.

Costa, who has battled hamstring problems in the pre-season, admitted he is still approaching full fitness.

"I feel very well, I'm coming off an injury but I'm getting minutes and I feel better every time out. I want to do better in order to get back to the national team. I'm working hard for that," Costa said.