Because he decided not to sell a young player that mean that he deal with young players enough?
Mourinho is famous for spending much Money to buy players that have already prove themselves.
I wont say this is bad but if we say that Jose deals with young players what we can say for Arsene for example?
IMO the last that mourinho cares for is the age of a player.
He looks for their potential,their abilities and decides with whom to work .Either if his name is De Bruyne or Lampard..
"Chelsea and Jose Mourinho have at a meeting where we clearly understand that Kevin for the new season to Chelsea returns. Chelsea will definitely no longer lend the player - at any club The thing is through - unfortunately.. It was no longer possible for us to be coupled to a transfer with Andre Schurrle."
-Bayer Leverkusen GM Michael Reschke. Source: Express via Sportschau (Google translated)
Now who said Mourinho doesn't deal with youth players enough?