Manchester United were desperate to sign the Euro 2016 winner back in the summer.
However, he ultimately ended up leaving Benfica for Bayern Munich instead.
Jose Mourinho took aim at the midfielder this week, claiming he was wrong to join the Bundesliga champions.
But Sanches has responded by saying he chose Bayern because they were more determined to sign him than United.
And the 19-year-old also said the world-class players at the Allianz Arena also influenced his decision.
Renato Sanches has revealed why he turned down Manchester United Man United return home after Anderlecht clash Fri, April 14, 2017
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"[Bayern] really put in a lot of effort and I immediately got a feeling the people in charge believed in me as a player," he said.
"That was the decisive factor behind my decision to join.
"Ancelotti always looks calm and in charge.
"You can just see he has a lot of experience.
"He is getting involved with his players a lot and is helping players to make individual progress.
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Renato Sanches believes he will continue to improve under Carlo Ancelotti
"But I am also playing alongside a lot of world-class players here.
"I can learn from all of them, especially from the players who play in midfield like Arturo Vidal, Xabi Alonso and Thiago Alcantara."
Sanches has endured a rocky first season at Bayern.
The teenager has been limited to 23 appearances across all competitions, and is yet to get on the scoresheet.