The Real Madrid legend will face United in the Champions League semifinals.
"What we have in common is that we love this profession," he told the Daily Mail. "Football is our lives. They are great professionals who look after themselves and who train properly. For Giggs to still be playing at this level at 37 years of age is incredible.
"He is still playing every three or four days and often in various positions - in midfield or out wide. He is still adding new things to his game and you can only admire that. Facing them again makes this match all the more special and I hope I can swap shirts at the end of the game with Ryan Giggs. It will be a great honour to have that shirt."