Marcelo Bielsa handed the England Under-20 international a Premier League debut against his former club Arsenal in December, bringing the youngster on at the very end of a hectic game of football which ended in a 4-1 defeat for Leeds.
Alongside a handful of cup appearances, his twelve-minute showing against the Gunners - forced by a significant number of injuries to the Argentine's senior players - was the only chance Greenwood was given by Bielsa in the two seasons the pair shared at Leeds, in spite of the youngster's goal-scoring prowess with the Under 23s.
Since Marsch has taken over at Elland Road, the American has included Greenwood in every one of his matchday squads and twice brought him off the bench to try and change the game as Leeds fight desperately to earn points to keep them in the top flight.
With substitute appearances against Watford and Wolves, Greenwood has shown Marsch that he deserves a place in the coach's thoughts, supplying Jack Harrison at Vicarage Road and Rodrigo at Molineux to score vital goals in the Whites' relegation battle.
Marsch has spoken openly about the difficulty of getting his players to 'unlearn' the principles in which his predecessor so thoroughly drilled them as, after three-and-a-half years at Leeds, the former manager's influence has lasted beyond his departure from West Yorkshire.
But the Whites boss has singled out Greenwood as an individual who has taken to his ideas well and is effectively executing Marsch's gameplan.
Though the managerial transition has not been straightforward, it's a change which has suited the young player.
"I think it's because since I was young, off the ball I've always worked hard," Greenwood said.
"He loves reactions off the ball - when you lose the ball, react straight away.
"I think that's my game, I suit his style of football basically.
"With Bielsa, it was man to man. With this style of play, you don't have to stay with your man - you can stay in between two men, and if it goes to the left side you can all go as a team to that guy.
"Instead of focusing on your man so much, you can jump to a different man and that suits me to a tee, basically, I love showing aggression and pressing off the ball."
Marsch arrived at Leeds United with a reputation for blooding fresh talent, and the prospects of Leeds' youngsters have also been significantly boosted by the promotion of former Under 23s boss Mark Jackson to Marsch's first team staff.
Greenwood is benefitting from working with a familiar face, as well as the culture of openness and communication that Marsch is working to create at Thorp Arch.
"[Jackson] is such an approachable guy. working with him before, you can always asked him anything," Greenwood told the Leeds United podcast.
"To be fair, all of the new first team staff are like that, it's more of a togetherness, you can talk to anyone.
"I think that's the way the gaffer has tried to make it be - if you've got something to say, it's such a good environment, you can talk to anyone about it which I think is really good for us as a club.
"It's a great atmosphere at the minute."