The club legend, who holds the games record with over 900 appearances, says the 19-year-old is one of those players that gets you out of your seat and that he is a 'proper Man Utd player'.
"Marcus has had a fantastic start to his career. He now has to go onto that next level and keep learning in every training session and every game," said Giggs.
"Marcus is one of those players who - I have been to Old Trafford a couple of times this season - as soon as he gets the ball you can feel it in the crowd," he said.
"You can feel the excitement. He gets you off the edge of your seat."