"It is a crucial department for us," said Mourinho.
"It is crucial because of the game we want to play and the intensity we want to have. We need alternatives and rotation and we need players to keep that intensity and that dynamic.
"In this moment it looks like we have a lot but when we get to September - and I am not talking October, November, December, January, I am talking about September - we have the Premier League, the Champions League, the Capital One Cup, a double national team fixture. 'When this time arrives, 22 players is not a big squad and when you can add more quality it is not a problem.
"It's a solution.
"A problem is for the managers without enough quality in their team."
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