Giggs gave a positive report on the 22-year-old two performances in recent Nations League victories over Finland and Bulgaria.
James provided a crucial assist for Cardiff City striker Kieffer Moore in the 1-0 win over Finland and, following a difficult second half to his debut campaign at United, Giggs has backed the former Swansea winger to come good again at Old Trafford.
He told WalesOnline, “He was excellent, especially in the first game. It was a lot to ask for some of the players who hadn't played for a long time to play two lots of 90 minutes.
"He's still young. If you go back 18 months he was just getting into the Swansea team, so it has been an interesting two years or so. He'll be all the better for last season's experiences.
“He'll look to start the season well and give Ole the problem of picking him. But with teams like United who are in Europe, you'll always have a lot of games, so you'll get plenty of game time, and when you do get the chance you have to take it."