"I think the right words are 'psycho-physical difficulties'. We don't know where the two meld together. We saw seven or eight players today who had heavy legs and slow minds. They are fired up for Serie A, play a fantastic game and then relax afterwards.
"This is a real problem. When you play a game with everyone at a high level, then it's difficult to think how many players to change," he added.
"We play better when absolutely concentrated, as the players step on the field with focus and it is easier. I personally need to work on their motivation and confidence.
"We are top of the Serie A table without the aid of luck and through to the Champions League knockouts with help from good fortune."