Chelsea manager Jose Mourinho has claimed Diego Costa, Ramires, Didier Drogba, Andre Schurrle and John Obi Mikel will need to pass fitness test before he decides whether will can be available for the match against Crystal Palace.

The west London side visit Selhurst Park on Saturday 18 October for a London derby with the challenge of maintaining their almost perfect start to the Premier League, securing six victories and one draw from their opening seven matches, which sees them at the top of the table.

When questioned in a press conference about the game and the potential absentees, Mourinho said: "We have some problems. Ramires and Drogba. Diego, Schurrle, Mikel. It is a long list."

Ramires suffered a muscle injury during the draw against Manchester City and has since missed the games against Bolton Wanderers, Aston Villa, Sporting Lisbon and Arsenal.

Drogba is struggling with an ankle injury, while Schurrle was ruled out of Germany's European Qualifier against the Republic of Ireland on Wednesday 15 October due to illness.

Nevertheless, the Portuguese boss highlighed his concerns about Costa after the Spaniard started in both Euro 2016 qualifiers, against Slovakia on 9 October and Luxembourg, three days later.

He said: "The Spanish team played in Luxembourg on Sunday. I gave them two days off [the Spanish players] so they had to report to train on Wednesday at 3pm. Diego was here Monday at 9am so you can imagine how strong he was."

Vicente del Bosque justified his decision to play Costa on an interview with AS, claiming he would keep naming the Chelsea striker for the national team if he plays regularly for Chelsea.

"All I said, and still say, is that Diego Costa, like any other player, will not play if he is not able to. But if he is well, he will play with the national team. The muscle injuries are very difficult to prove," Del Bosque said.

When questioned about his relationship with the Spain manager, Mourinho said: "I don't speak with national team managers unless they want to speak with me.

"I don't lose my time contacting national team. During my career, some of them used to contact me and ask me about the situation of players. They have the power. We don't have the power."