Beckham, who is on-loan at AC Milan, is set to face his former club United on Tuesday in the last 16 of the Champions League.
“We are different in the sense he has been in the limelight, front page and back, while I prefer to keep myself to myself,” explained Giggs.
“But I still speak to him. He has not changed as a person.
“He has always loved football. He has always been dedicated and that is still the same now.
“Like myself, Becks looks after himself.
“He is naturally fit and is a natural athlete, so I am not surprised he is still going at all.
“In fact I reckon he will keep going for another three or four years.”
“We had a couple of chances to meet when he was at Real Madrid but it is great that it will finally happen and great for Becks to come back,” he continued.
“It will be fantastic for the fans to see him again because he was a great player for United and still is a great player for England and Milan and in America as well.
“I hope he doesn’t do anything nasty to us. He is a quality player and has always risen to the occasion. Hopefully he will enjoy it – but not that much.”