John Swift, Nathaniel Chalobah and Patrick Bamford will leave on-loan this season.
Mou told chelseafc.com: "The other ones who are a bit older, 20 or 21, we feel they need to compete against men in a different league, people like Bamford, Swift, Chalobah. They are ready to go to other clubs and have a good loan.
"What we are trying to do, and we believe we are going to be successful, is in a few years’ time, when they are between 20 and 23, we will have them back at the right moment and in the first-team squad."
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