Mourinho has put their differences to one side by hailing the Frenchman, who won three Premier League titles during his 22-year reign at the North Londoners.
Speaking to beIN Sports in France, he said: "The easiest way to remember him is to say that he is one of a kind.
“In today's football, it's impossible for a coach to be 10, 15, 20 years in the same club, it's the last one.
“I really do not think we'll see a coach stays 10 years in a club, now the players go, the players come, the pressure is immense for the coach, you do a good season, but the next one is a bit worse.
“There is a huge pressure, a tendency to the rules of today say that coaches do not stay long, if we talk about football, Wenger is a trainer of the invincible, (Claudio) Ranieri, for example, is a coach that I call 'the miracle', title of champion of Leicester .
“Wenger is one of the Invincibles: he won the Premiership with Arsenal without losing a game and that lasts over time."