James, who moved to Old Trafford from Championship side Swansea last summer, has been a regular starter for Ole Gunnar Solskjaer’s side in 2019/20.
The winger scored four goals and set up seven more in the second tier last season, but some questioned whether he would be able to make an immediate impression in the Premier League.
James has made the step up look simple, though, scoring three goals and provided six assists in his 21 Premier League appearances to date.
His pace has aided United’s counter-attacking approach and Rashford – scorer of 14 goals in the top flight this campaign – is one of those who has benefited from James’ work on the wing.
And the England international praised his team-mate’s work ethic and quality, and backed him to continue making progress at Old Trafford.
“Dan has been brilliant since he came in,” Rashford told United’s official matchday programme. “He works hard in every single game and, when it comes down to it, that is all you can ask of each player – to give it all they have got.
“He definitely does that and, if we can adapt more to his playing style, he can cause some teams nightmares down the right-hand side, as we’ve seen in some games this season.
“But I like his deliveries as well. He takes his time and does not just cross it. He lifts his head up and tries to pick you out. It’s these little things that, as time goes on, he will definitely improve on and build on.”