The teenager has scored six goals for United this season, including the deciding goal in last night’s 1-0 Champions League win at Benfica.

And Giggs, who won 13 Premier League titles during his time at Old Trafford, thinks the England international can get even better.

“Marcus has had a fantastic start to his career,” he told Sky Sports.

“He now has to go onto that next level and keep learning in every training session and every game.

"He 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.

"You can feel the excitement. He gets you off the edge of your seat."

Rashford has been on fire this season but joined Jose Mourinho’s ever-growing injury list last night after he ‘felt something in his knee’.

The forward has developed a prolific partnership with summer signing Romelu Lukaku and Mourinho is hopeful it isn’t serious.

The win in Lisbon was Manchester United’s third victory in as many games in Europe this season, keeping them top of Group A.

They return to Premier League action this weekend as they travel to struggling Huddersfield.