The 19-year-old opened the scoring for United in a fantastic 5-0 win against Bundesliga side Red Bull Leipzig at Old Trafford on Wednesday night.
It was Greenwood’s first start in the Champions League and it was the teenager’s second of the season in all competitions.
The striker has had a difficult start to the campaign after being sent home from England duty after breaking Covid-19 protocols and he was also reportedly left out of Manchester United’s squad to face Newcastle earlier this month after being late to training, though Ole Gunnar Solskjaer denies the claims.
There’s no doubt of the teenager’s potential and many at the club are wary of the expectations on him, particularly in a traditionally tricky ‘second season’ in the first team.
But Rashford – who scored a hat-trick after coming off the bench – says Greenwood can become whatever he wants to be if he remains professional.
‘Mason [Greenwood] just needs to keep his head down and keep working and he’ll be an unbelievable player for us,’ said Rashford.
The England striker started the game on the bench as Solskjaer has one eye on Sunday’s visit of Arsenal to Old Trafford.
But Rashford says the side deserved their victory against the Germans for their defensive discipline, which eventually allowed the attackers more space as Leipzig went in search of an equaliser.
‘It was a real team performance,’ said Rashford.
‘The ones who started did well and the substitutes did well too. We can’t ask for much more than that in terms of the attitude and the intent to go and kill the game off. It worked in our favour.’