Rooney, now 22, laughed: "I can remember his hair because he used to have a big mop-head.
"Seriously, his talent and dedication are great. He helps all the players.
"He's definitely a big help to me and the way I play my game."
Giggs is closing in on Bobby Charlton's record of 759 United appearances.
Rooney added: "It's right that with his dedication and hard work he should end up with most appearances for the club.
"He's an old-fashioned winger, he's clever and can play you in behind defenders.
"He's one of the best players of all time.
"Giggs is just the perfect role model for younger players growing up."