The Belgian international is expected to join Bundesliga side Wolfsburg in a £17 million deal in the next 48 hours.
Mourinho said: “Kevin has a chance to go. He's a player that Chelsea have had a couple of proposals for. We keep analysing them, and one is coming to a level where we believe it can be a good situation for the player and also the club.
“We know he's a fantastic young player with lots of potential. I still say I would be happy to keep him and develop him, but you have to analyse the player's profile and personality. Probably, he wants so much to go that maybe it's a good option to let him go in a very good deal for the club financially.
“The fee is not agreed, but I believe we will reach an agreement. The interest is big from the club, even bigger from the player.
“We don't need a direct replacement. The reason why we opened the door is because is a position where we have options.”
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