Manchester United boss Sir Alex Ferguson says Cristiano Ronaldo needs a Champions League winner's medal to be considered the world's best player.

He said: "Six players in today's squad have won a Champions League medal - Ryan Giggs, Gary Neville, Wes Brown, Owen Hargreaves and Edwin van der Sar, as well as Paul Scholes who was suspended for the 1999 final.

"I know the others are keen to join them.

"We are rating Cristiano Ronaldo the best player in the world. But he needs the medals to prove it."

Ferguson also paid tribute to his new signings.

He added: "Carlos Tevez has a marvellous understanding with Wayne Rooney.

"Owen Hargreaves has adjusted quickly, Anderson has been a revelation and Nani is getting better all the time."