The Mexican striker is regarded as buy of the season after joining United from Chivas last summer for just £7million.
“The season he has had is incredible,” Rooney told the club’s official website.
“Nobody expected this from him. He is a nice lad who works very hard in training. We often stay out a bit longer and do a bit of finishing work together in order to try and improve.
“He is playing every week now and scoring a lot of goals.
“What he has done is quite incredible. It wouldn’t surprise me if he ends up scoring the winning goal in the final to top it off.”
“The position I’ve been playing, just behind Javier, has been working well for the team,” Rooney continued.
“I do need to help out in midfield when we don’t have the ball. But I also feel I could influence the game in the way I’d like.”
