Rooney insisted he was not interested in what his former team-mate had to say after the ex-England midfielder suggested the striker had burnt out because he started his professional career as a teenager.
But Beckham feels that Rooney is still an asset for both club and country, and is a fear for opposition sides when they see his name on the teamsheet.
|33/1||Wayne Rooney is 33/1 with William Hill to be top scorer at the World Cup|
"I’d always back Wazza [Rooney] because he’s a great talent and he’s a great player for England. Every time he’s stepped out in an England shirt, he always gives 110 per cent," he told the Daily Mail.
"Scholesy is a person that knows Wayne as well and has been around him for quite a few years and everyone is entitled to their opinion but not everyone is going to agree with it.
"In the games I’ve seen him play for United, he’s been the shining light. But Scholesy’s been around him more than I have.
"He has always been about more than just scoring goals, he’s a goalscorer but he works hard for the team and that is what Wayne’s game has always been about.
"If he doesn’t score goals he’s either assisting or creating something for the team and working hard for the team. I think for the opposition to see Wayne Rooney on a teamsheet, that scares them."
Beckham, who was in Miami to see Roy Hodgson's side draw 0-0 with Honduras in their final World Cup warm-up match, also praised Liverpool's Raheem Sterling ahead of the tournament in Brazil.
The 19-year-old missed out on a start against the Central American side after being sent off against Ecuador, but Beckham believes his form at club level means he could still gain a starting berth in Brazil.
"I think he’s a great talent, he plays with the flair of a kid who goes out and just plays.
"The games I’ve seen him play for Liverpool and England, he’s just stepped into a role and deserves to be here."