The French left-back will be key in stopping Barca dangerman Lionel Messi as he did in the two legs of last season's semi-final.
Giggs said: "Patrice is a top defender. He is known as an attacking full-back but defensively he is underrated - he is so good.
"What he did last year in two games on a booking against Messi, knowing if he got another yellow he'd miss the final, was fantastic.
"It is the ultimate challenge, like facing Cristiano. They are the two stand-out players in the world at the moment and you have got to be on your game for 90 minutes."