London - The likely absence of Diego Costa should not stop Chelsea staying in command of Group G of the Champions League, with the Premier League leader a big favourite to beat Maribor at Stamford Bridge on Tuesday.
Chelsea manager Jose Mourinho is unsure when Costa will be back after the striker returned injured from international duty after playing back-to-back games for Spain.
Didier Drogba or Loic Remy will fill in if Costa is not available for Chelsea, which is top of its group with four points from two games. Maribor and Schalke have two points and Sporting has one.
Costa has been carefully managed by Mourinho in his first season at Chelsea, with the striker hindered by persistent hamstring problems that affected him at the end of last season at Atletico Madrid.
Mourinho does not believe Costa is fit enough to play more than one game a week, so was unhappy to see him play the full match against Slovakia and 82 minutes against Luxembourg in the recent international break for European Championship qualifiers.
Costa, who has scored nine goals in his first seven Premier League games, was not even a substitute for Chelsea's 2-1 win over Crystal Palace on Saturday, a result that kept the team top of the standings and preserved its unbeaten start to the season.
"He will play for me when he has free time from the national team," Mourinho said sarcastically after the Palace match.
"I think Diego will be in great condition again in mid-November, to be back for the national team. That is for sure."
Remy replaced Costa against Palace, but Drogba started in the 1-1 draw with Schalke in their opening group match in the Champions League and could be preferred again in Europe.
Slovenian champion Maribor has traveled to England in each of the last three seasons in European competition and lost each time. And none of its opponents had the pedigree of Chelsea.
Birmingham, Tottenham and Wigan all won in the Europe League against Maribor, whose record in six games against English opposition is one win, one draw and four losses.
Maribor's last trip to Britain was successful, though beating Scottish champion Celtic in the Champions League play-off to claim a place in the group stages.
And Ante Simundza's side has started Group F well, drawing 1-1 at home to Sporting thanks to a stoppage-time equalizer and then by the same score away to Schalke.