Valencia has been in fine form for Manchester United this season.
The veteran has fought off competition from Matteo Darmian to establish himself as the club's first-choice right-back.
His impressive displays also saw him extend his contract with the club last month.
And Valencia has paid tribute to Mourinho – believing the former Chelsea boss has given him the confidence to thrive.
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Antonio Valencia has paid tribute to Manchester United boss Jose Mourinho
Antonio Valencia has impressed under Jose Mourinho this season
"I think, when you are playing with confidence, you do things differently," he told United Review.
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"I have to thank the manager in that respect for the backing he has given me.
"I thank him for his kind words and it’s definitely an extra motivation. I'm working very hard for sure.
Antonio Valencia is above Matteo Darmian in the pecking order
"So far this season, things have been going really well for me and it’s the backing of the manager that has given me a real confidence boost."
Valencia is expected to start when United go up against Watford tomorrow (3pm).