I think it's really sensible of Klopp to take a no excuse approach to the Liverpool role, to be honest.
For too long under Rodgers, and Dalglish before him, we were too often reliant and caught up in storms which surround Mourinho. We scape-goated officials, things like tiredness, and scheduling etc.
He knows he hasn't got the squad size to rotate, but the nuance of saying that we have no excuses will reverberate around the club. It puts the onus on all of us, and the fans (given his comments surrounding them leaving early) to give this season and every single match our all.
Of course, away from the cameras and the public eye, I think we all know that tiredness would be an issue post-travelling to Kazan (5,000 miles). I think it's shrewd of Klopp, though. We must always play until the final whistle, and no game is lost before we go out onto the pitch.