Tipped to become an Old Trafford star as the forward came through the academy, the 19-year-old shone during his breakthrough season and scored 17 goals in 2019-20.
But Greenwood has struggled to hit the same heights this term, scoring just six times in 40 appearances in a campaign that started with him being sent home by England days after his senior debut.
The teenager has been getting back to his best recently, though, and headed home on Sunday to secure a late 2-1 comeback win against Brighton.
"I'm getting back into the zone, really – somewhere I wanted to be earlier in the season but it's come now," Greenwood said.
"I never had my head down, always concentrated, always worked off-scenes in training and I'm happy it's coming out onto the pitch now."
Greenwood's recent uptick in performances has led to regular praise from manager Ole Gunnar Solskjaer, as well as a new deal at Old Trafford until at least 2025.
The 19-year-old has scored in back-to-back games for the first time this season and his manager was delighted by his poacher's effort against Albion, with his diving header the reward for hard work on the training ground.
"It was very important," Greenwood said after his first Premier League goal since September.
"Brighton played well, they defended well and obviously to get the winner means a lot to me.
"I didn't really see after I headed it. I just saw after it went in the back of the net to see if it was my goal – I knew it was my goal.
"I'm happy to score a header. I've been working on them all season in training and I'm happy one came off.
"It was one of my weaknesses, I'd say. To be a striker, to be an attacker, you've got to do all things and heading was one area where I was weak on.
"But with practice and help from the coaching staff it's obviously strengthened now and I'm bringing it out onto the pitch."
United showed impressive spirit on Sunday to consolidate their place in second spot and now turn their focus to Thursday's trip to Granada in the first leg of their Europa League quarter-final.
"Coming back after the international break, it's always good to get a win," Greenwood told MUTV.
"Obviously it's a spring in our step onto the game in the Europa League and I'm sure we'll do well in that as well."
Brighton boss Graham Potter was frustrated to come away from Old Trafford with nothing, having taken the lead through Danny Welbeck.
The former United striker's early goal was cancelled out by Marcus Rashford, with the 30-year-old denied a penalty after a challenge by Harry Maguire before Greenwood's winner.
"Over the course of the game we did a lot well, but when you're 1-0 up you want to try and hold on and get something," said Potter, whose side are six points above the relegation zone.
"On another day we could have done that. We just need to move forward to the last eight games and get the points we need."