Jose Mourinho is unconcerned by Diego Costa's long-term fitness, despite the striker remaining a doubt for the start of Chelsea's Premier League title defence against Swansea City.

Spain international Costa enjoyed a fruitful first season at Stamford Bridge, scoring 20 league goals.

However, hamstring and thigh injuries blighted his campaign and his fitness problems resurfaced as he was declared unavailable to play in Sunday's Community Shield defeat to Arsenal.

Manager Mourinho is calm about Costa's situation, though, and stated that he is more than happy to use Radamel Falcao or Loic Remy as alternative options in attack.

"I don't know [if Costa will train later on Friday]. I promise you I don't know," said Chelsea's manager ahead of Saturday's visit of Swansea.

"I have Remy and Falcao, and I'll go with Remy and Falcao like I did in other matches and like I did last season with Remy and Didier Drogba.

"Everybody wants top strikers. [With Costa it is] not just for the goals he scores, but the football he produces and the mentality he helps to create in the team.

"I don't like to say I don't need him, but I don't like to talk about injured players. The last thing I do if we lose is to say we played without this one or that one.

"I think he is going to train with the team, his reaction after that and his decision to be confident to play is a different story.

"I prefer a situation where the player is never injured, never has problems and is at the top level during 10 months of competition, obviously.

"But there is nobody to blame. That's important. I can't blame the player because he works hard. The medical department, I completely trust in them. I have nobody to blame.

"I'm calm, positive. I believe he'll be with us for many, many matches."