Former Bayern Munich chief exec Karl-Heinz Rummenigge admits he's long been a fan of Manchester United striker Cristiano Ronaldo.

Rummenigge isn't surprised seeing Ronaldo make the impact he has with United since his return.

He told BILD: "He [Cristiano Ronaldo] is a phenomenon. He is 36 years old, has played for 20 years at the best level. He has an upper body like Adonis.

"I remember a scene when I was Turin [at Juventus].

"Suddenly he was standing behind a door with his hands in the air. I asked him what he was doing and he replied: 'I'm practicing the celebration of my next goal...'"