Bruce sold Valencia nearly three years ago and United can thank their legendary defender for helping to stave off interest in the Ecuadorian winger from the elite clubs of Europe.
"There was a lot of interest in Antonio that summer," Bruce told the Manchester Evening News.
"We both felt it would be a feather in Wigan's cap to have a player transfer to Manchester United. There was big, big interest from Real and Bayern, amongst others, but we did our best to point him in the direction of Old Trafford.
"Apart from anything else, I thought he was a Manchester United player and he'd handle the step up well. It was his call in the end, but after our input and a chat with Sir Alex, his mind was set.
"I am so glad because he is a terrific lad and a great professional.
"Even some of the very best players have found it difficult to come to terms with the intensity of being a United player. You have to hit a very high level every week. Some have fallen by the wayside.
"But I always felt Antonio's temperament would help him. He is a very quiet unassuming guy but very strong mentally. His mentality is terrific.
"It was never easy coming in after Cristiano Ronaldo even if he wasn't a direct replacement. But Antonio just got his head down and did what he does best."