The Spaniard scored just 12 goals in 44 games under the Special One last season but says the two men enjoyed a productive professional relationship.
Fernando Torres says he learned a lot from Jose Mourinho in his final season at Chelsea.
Torres ended a disappointing three-year stay at Stamford Bridge last month by agreeing to join AC Milan on loan for the final two years of his contract.
Mourinho frequently criticized Torres and fellow strikers Samuel Eto'o and Demba Ba last season, and the lack of a reliable scorer was widely perceived to be the main reason why Chelsea fell short in the Premier League title race.
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The Spaniard scored just 46 goals in 172 games for the Blues after joining for 62 million euros from Liverpool in January 2011 and netted 12 times last season under Mourinho, but says he enjoyed a productive working relationship with the Special One.
"I had a professional relationship with him," Torres told reporters. "I learned so much. When I told him that I was going to Milan he wished me good luck, and he told me about the passion for football that is here. I wish him all the best, as he has done with me."
Milan CEO Adriano Galliani said it was "better late than never" to have signed the striker after he failed to tempt him to San Siro in 2004.
"Fernando is an incredible champion," he said. "He has won everything there is possible to win. Fernando began his career in Madrid, and even then it was clear that he was something special."