The Ghana international signed a 17-month deal with the Serie A side on Monday after being allowed to leave Stamford Bridge on a free transfer.
The 31-year-old midfielder had been limited to just two Premier League starts this season after returning to west London following a loan spell at Real Madrid last season.
He’s given everything for the club and a great chance arrived for his future
And Mourinho believes that the move will prove to be in the best interests of all concerned.
“He’s a player everyone loves in this club but it is a fantastic situation for him and we didn’t want to stop him,” said Mourinho.
“He deserved that the club let him go on a free transfer and with Nemanja Matic we covered the situation in midfield and we could let Michael go.”
Mourinho added: “He’s given everything for the club and a great chance arrived for his future.
“I know he can continue to play at a high level and I wish him success and happiness in Italy and at the World Cup in Brazil.”
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