The Hoops boss has been discussing team news before Thursday's game.
Indeed, speaking to reporters ahead of the crunch European clash, the Norwegian admitted it is too early for the defencer-cum-midfielder to return for the Bhoys.
Summer signing Jozo Simunovic, however, has been classed as a possibility by Deila.
Winger Stuart Armstrong, meanwhile, is also training with Celtic once more and is therefore available to face the Turkish side.
RD: Jozo Simunovic could be a possibility. Stuart Armstrong is training again & is available, but it’s still too early for Charlie Mulgrew.— Celtic Football Club (@celticfc) September 30, 2015
Fenerbahce is really a must-win game for Celtic if Deila's men have any aspirations of making it out of the group stages. It won't be the end of the world if they lose, while a draw could be considered a good building block after the opening stalemate at Ajax.
But the Hoops, of course, need to capitalise on their fierce home atmosphere and will have their best chances of winning games in the Europa League at Parkhead.
After the Fenerbahce clash, Celtic travel to Hamilton, having closed the gap behind Scottish Premiership leaders Aberdeen at the weekend, despite dropping points during a 0-0 draw with Hearts.