Jose Mourinho concerned World Cup stars will not be ready for Chelsea's Premier League campaign

Quartet may not be ready for opener against Burnley on 18 August

André Schürrle takes some orders from Jose Mourinho (Getty Images)

Chelsea manager Jose Mourinho fears four first team players will be missing when the Blues face Burnley in the opening match of their Premier League season.

The title challengers face the newly-promoted Clarets at Turf Moor on 18 August, but Mourinho could be without Andre Schurrle, Oscar Willian and Ramires after their involvement in the latter stages of the World Cup.

Speaking after the 3-0 defeat to Werder Bremen, in which Mourinho blasted the referee Harm Osmers who “killed the match”, Mourinho said his squad is far from ready.

"Eden [Hazard] trained two days, Didier [Drogba] trained three days. They need these matches to look for their form," he said.

"It worries me because the boys (returning late from the World Cup) that start tomorrow don't have time to get ready for the start of Premier League.

"We cannot deny that our first half was poor. The reaction was good in the second half. Eden brought something to the game."

Mourinho was handed a big boost by the Belgian who impressed in a 33-minute cameo - though he was unable to change the result.

Hazard said: "We tried to improve and be ready for the first game. Today was difficult, pre-season is always difficult.

"I'm happy. It's a pleasure to be back on the pitch with the team and I try to give my best my it's my first minutes. I hope my next game will be better.

"It's always difficult to play against a smaller team as they give everything because they are playing against Chelsea."

The 23-year-old also revealed he was able to "enjoy" his month off after the World Cup.

He added: "I enjoyed one month (off) - it was easy. I didn’t' think about football, but now I'm back. We will try to win (our next match) and give the best to be ready for the first game."