Rooney reveals biggest fears
The forward said he was well aware of the threat Seedorf posed after the Dutchman helped Milan knock United out of the competition in the 2004/05 and 2006/07 campaigns.
"Seedorf (is the Milan player I fear most). He's probably the best player I've ever played against," Rooney told Tuesday's La Gazzetta dello Sport.
"Rarely have I seen a player do what he does on the field. You can't leave him out."
Rooney added that he was looking forward to taking on his England team mate David Beckham on the former United player's return to Old Trafford.
"David is a champion and he represents United's history," he said. "I hope he gets a great welcome. It'll be exciting to play against him."
He also echoed Beckham's comments that Capello's stern approach was a big part of his success, after England easily qualified for this year's World Cup finals in South Africa.
"He scares us, like a strict father," Rooney said. "He's made us more of a team. He's worked above all on the tactics. Now we change them for every match."