You never want to use the excuse of being tired for a bit of bad form but it can be a reason I suppose.

Successful team = unchanged side and games in the Championship can be played at a ridiculous pace and ferocity.

Not making any excuses but tiredness could play a factor, especially if a good few of your players are used to playing at a leisurely tempo with the Mediterranean sun on their backs
Last time we lost a league game we went on an incredible run which ended today.

Time to regroup and go on another one.