As Rooney was hitting his 200th goal for United against Bayer Leverkusen in the Champions League on Tuesday, Kompany was playing his first game of the season for City as they eased past Vikoria Plzen.
Now Kompany is looking forward to coming up against Rooney, who is showing a rich vein of form following a summer of speculation about his future.
"It's brilliant he's doing so well again," said Kompany.
"You want to play against top players at their best. That's personally how I feel about it.
"I always want to play against players when they are at their best. I'm really happy for Wayne that he's on top form.
"This is the great thing about the Premier League, you play against top strikers all the time. But there are many players to watch out for in both teams."
David Moyes goes into the game, which you can see as part of Super Sunday on Sky Sports, with a great record against City having won 10 of his previous 14 games against them.
But Kompany says that Moyes' previous successes will have no impact on Sunday's game.
"It's a different team, it's a different season and I would say there has never been anything too predictable in the derby," he said.
"Nobody predicted we would win 6-1 at Old Trafford, that they would beat us at the Etihad and that we would win at Old Trafford.
"The derby is always a game you look forward to. And I don't think it's just the people in Manchester, but all over the world who look forward to enjoying it. It's a game that attracts a lot of attention.
"I never take it for granted and I feel blessed that I am able to participate in those games. You do your best to make sure you play well in these games."