David Beckham says Cristiano Ronaldo should return to Manchester United if he decides to leave Real Madrid.
Ronaldo took Beckham's number seven shirt when the former England captain left United for Real Madrid in 2003.
Ronaldo, 30, who won the Balon D'Or for the third time last year, joined Real for a world-record £80m in 2009 but his contract expires in 2018.
"If he decides to leave Real the only place he should go is back to United," said Beckham.
Ronaldo has been linked with another of Beckham's former clubs, Paris St-Germain, should he leave the Bernabeu.
But Beckham - who returns to Old Trafford this weekend where he will play for a team managed by Sir Alex Ferguson in his 'Match for Children' in aid of UNICEF - thinks United would be a better destination for the Portugal striker.
"I'd have crawled back if I could," said Beckham, who made 394 appearances and scored 85 goals in an 11-year United career.
"I'd never advise anyone not to come back to United."