Chelsea striker Diego Costa declares fitness for Arsenal clash

Chelsea striker Diego Costa has claimed that he is "certain" he will play against Arsenal on Sunday, despite suggestions that he may not be fit for the Premier League clash at Stamford Bridge.

Blues manager Jose Mourinho recently revealed that Costa struggles to play in more than one game a week due to hamstring issues.

After the Brazil-born Spain international started in Tuesday night's 1-0 victory over Sporting Lisbon in the Champions League, there were doubts whether the forward would be in the lineup for this weekend's battle.

However, Costa has told reporters: "Of course I will play against Arsenal. I am certain. I played 90 minutes [in Lisbon] and now I can have a rest. I do not see a problem.

"There are a few niggles that are annoying me, but I am working to treat them during the week with the physios and the medical staff. Every day I feel closer."

So far, Costa has scored eight goals for Chelsea following his summer arrival from Atletico Madrid.