Rashford channelled this frustration in the right way, as he made the perfect impact from the bench by scoring United's third goal in the resounding win.
"I think you could see that in his celebration, he was fuming," he told Premier League Productions in quotes published by The Metro.
"But when two legends of the game are playing ahead of you it's hard to complain in a sense.
"He's never going to drop Ronaldo, he needed somebody else in there and Cavani was fabulous last season. He probably deserved to start sooner.
"Having Rashford and Greenwood to come off the bench, as much as it will hurt them, was maybe right for the balance of the team. They looked good, and Rashford will get goals coming off the bench, definitely."
The former Red Devils midfielder believes it was an ideal reaction to the 5-0 mauling by Liverpool, and believes Ole Gunnar's Solskjaer's team selection was the right step forward heading into Sunday's game against Manchester City.
"I think it has to be considering the amount of goals they've conceded; it shored them up defensively.
"But the big question is they've got Manchester City at OId Trafford on the weekend. You're not going to have much of the ball and you're going to be quite deep. They defend with seven then Bruno [Fernandes], Cavani and Ronaldo.
"Is that going to work against City? We'll see. But I think today was a big step forward."
Fuming at the manager??! We won the game ♂️ that celebration was pure relief! It's been a hard week... https://t.co/qHCg5x268u- Marcus Rashford MBE (@MarcusRashford) November 1, 2021
Since Hargreaves' quotes were published, Rashford has since taken to twitter to refute the former Manchester United midfielder's claims saying that the celebration was purely an expression of relief after a tough week.
United's next game before facing City is against Atalanta in the Champions League on Wednesday night.
They head into their Italian assignment sitting top of Group F with 6 points from 3 games and are currently on course to secure a place in the last-16.
Then, the following match against City on Saturday comes at the end of what could be a game-changing seven days for under-fire boss Solskjaer, who came under increasing scrutiny before Saturday's much-needed victory over Spurs.
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