Whiteside has been impressed by how quickly the Mexican has settled at United.
"He had a great World Cup and looks like a really good prospect," he told the Manchester Evening News. "He's a natural finisher with good speed, which is crucial in the Premier League.
"So many people would struggle to cope with the pressure of a move to United, but I don't think the manager will have any worries about his temperament.
"He showed in the World Cup that he doesn't get over-awed by the big occasion - so he shouldn't have any problems playing in front of massive crowds at Old Trafford. He looks like he was a real find."