The Norwegian is certain the Bhoys won't face a tougher test than Qarabag provided them with.
Indeed, such was the test Qarabag gave Celtic, Deila immediately declared after the qualifier that the Scottish champions' next opponents (in the play-offs) certainly won't be a better side than the Azerbaijani outfit.
Celtic drew 0-0 away from home during the second leg on Wednesday night, having beaten Qarabag at Parkhead thanks to Dedryck Boyata's solitary winner.
As such, the Bhoys only progressed by a very narrow margin indeed and Deila is confident no side they will now face will be any better than Qarabag.
Celtic manager Ronny Deila speaking to the media in Baku: I'm very happy. it was an exciting game. There was so much nerves. (MD)— Celtic Football Club (@celticfc) August 5, 2015
Celtic fans will certainly hope that's the case, as the Hoops couldn't have left things any tighter during qualifying in Azerbaijan, under pressure until the last minute.
Deila's men find out who they will face in their play-off during Friday's Champions League draw.
Can the Bhoys go all the way this time or will they have to improve vastly not to leave things too close for comfort in the next round?