"It is basically sad because I feel Mourinho is a manager of quality," Wenger told the club's official website .
"I am a great believer in technical stability and therefore I don't think it is good news for football."
On their fractious relationship Wenger added: "We didn't get on the best, but recently it has become better.
"That does not hide the fact I respected what he did and the quality of his work.
"Of course he is a great manager. He arrived when Chelsea were on the way up; they had a good side already and he did something more and made them winners.
"He deserves a lot of credit for that because it is never easy to win and in England it is maybe more difficult."