The pair played together at Old Trafford for five seasons, winning three Premier League titles and a Champions League trophy in that time.
Rooney said of the Real Madrid star: "If you've got Cristiano Ronaldo in your team, you don't take away from him what he's best - and that's being fresh and being ready when win the ball getting to score you a goal.
"If you're asking Cristiano Ronaldo to chase full-backs and run back in you're taking a lot away from his game.
"It probably does [take a lot from Rooney's game], but at the time he was the more dangerous player and he's the one who's going to produce that magic which is going to win us games.
"As a I said before we're a team you didn't mind doing that.
"We had a good compromise because me and Tevez would do a lot more work defensively than Cristiano.
"But with Cristiano, you knew he would win us those big games with the big moments. With any other player, you probably wouldn't but with Cristiano, he was that good you had to accommodate him.
"I would gladly do that for him to score big goals and help us win trophies."