If Ruben Amorim had stayed in charge of Manchester United, Kobbie Mainoo would be speaking to prospective clubs right now about leaving - if he hadn't departed already. Instead, the homegrown midfielder is thriving under Michael Carrick and looks every bit United’s present as well as its future. With every game he plays, Mainoo is making Amorim’s decision to disregard his talent seem all the more ridiculous.Thomas Tuchel now must make sure he does not make the same mistake as Amorim. Mainoo came out of nowhere to make it into the England senior squad in March 2024, bypassing the Under-21s on the strength of his mature displays under Erik ten Hag. He shone when given the chance under Sir Gareth Southgate and soon established himself as a regular, starting all of England’s knockout games at Euro 2024 as they reached the final. And yet he has only played once for the Three Lions since, as a substitute in the Nations League away to Ireland. Injury prevented Lee Carsley from picking Mainoo again for his remaining matches as England boss, and the midfielder was recovering from a hamstring problem when Tuchel selected his first squad as national team coach in March 2025. By the time Mainoo was fit again, he was on the periphery of Amorim’s squad and it was highly understandable that Tuchel chose to look elsewhere in the next four international windows.But now that Mainoo is playing a pivotal role in United’s resurgence under Carrick, Tuchel cannot ignore him any longer.Mainoo’s second coming has almost been as breath-taking to observe as his initial breakthrough into the first team as a teenager under Ten Hag in November 2023, when he looked like the classiest player on the pitch in his debut at Everton and never looked back.While everyone knew what Mainoo had once been capable of, it was not unreasonable to assume that his powers had faded during his long exile from the team. In his 11 appearances this season as a substitute under Amorim, the longest of which clocked at 45 minutes, he was largely ineffectual. His only start of the season, at Grimsby Town, had resulted in United’s most humiliating cup exit ever. Mainoo did not exactly rip it up when Darren Fletcher handed him a start in the FA Cup against Brighton, either, and his confidence seemed drained, the smile gone from his face.But he has looked reborn under Carrick. Mainoo has covered more ground than every other United player in three of the last four matches, making a mockery of Amorim’s apparent belief that he lacked the physical attributes to thrive in his system, or even at this level.Against Tottenham, Mainoo won the most duels and had the most take-ons of any United player. His crafty lay-off to Bryan Mbeumo for the opening goal on Saturday was his second assist in four games, with his only other this term coming on that fateful night in Grimsby.Mainoo has also embraced his combative edge in the last four games while he has taken his passing game to a new level. If he can be this good after almost a year of not starting games, just imagine how good he would have been had he played each week under Amorim.Gary Lineker joked on Monday that Mainoo should consider suing the Portuguese for the "detrimental impact" he had on his career, although no one watching the midfielder play with such confidence and such fluidity against Manchester City, Arsenal, Fulham and Tottenham would have been able to guess he had gone eight months without starting a Premier League game.Carrick warned against "putting all this on his shoulders and expecting so much of him" given how long Mainoo had been on the margins, but he also praised him for slotting straight back into the team."Credit to him he's come right in and found his rhythm of football, which is not easy after a period of time out," Carrick said on Saturday. "There's definitely more to come from him, and that's just the age he's at, the stage he's at in his career. He's just starting out, really, essentially. And he's got so much experience under his belt, of big occasions, big games, and pressurised situations."And the prospect of the biggest games and the most pressurised situations, at a World Cup, is back on the horizon.Add GOAL.com as a preferred source on Google to see more of our reportingEngland's midfield is a more crowded marketplace than in 2024, and Tuchel seems very fond of the double-pivot of Elliot Anderson and Declan Rice he stumbled upon in September. He also seems to have a lot of faith in Jordan Henderson, whom he has called into all five of his camps due to his experience and the pastoral role he can play. Then there is Nico O’Reilly, who has played as left-back for England but who has looked even more useful for City since being deployed in midfield. But Mainoo has something that no England midfielder has, an ability to receive the ball in almost any situation and be comfortable with it. England have struggled to control games with possession for more than 30 years, but Mainoo, who Lineker described as being the Three Lions' best player at Euro 2024, can give them a tighter grip on proceedings."Kobbie is very special in the sense, from my experience looking at international football, that sometimes you can lose because you lose control of the game," former England and United midfielder Owen Hargreaves told GOAL. "And we've got a lot of great players. We can't play all the 10s, but one thing Kobbie gives you, you can pass him the ball at any point. You need that in international football because you look at that young man, he hasn’t played for a year, then you play the two hardest teams in the league (City and Arsenal), which have the most possession in the league and you can pass and show courage."I'm just really proud of him the way he's just started to play after not playing for a year. And I'll be honest, I don't think I've ever seen him ever play a bad game. For a young man to achieve what he's done, score the winning goal in the FA Cup final, have an impact on the international stage, not play for a year when you're probably one of the best young players in the country, then to just play the games that he has tells you all you need to know. Imagine what he's going to be like as he gets older with more experience."Tuchel has tended to favour more experienced senior players, hence him bringing back Henderson and Marcus Rashford. His short-term contract with England gives him less motivation to blood younger players with potential, and the World Cup this summer looks set to be his one shot of glory, meaning he understandably doesn’t want to experiment. England have fared pretty well without Mainoo, winning all their qualifiers without conceding a goal, but another thing Tuchel likes to do is foster fierce internal competition for places, and give everyone a gentle reminder that their pace in his starting line-up or even his squad is not guaranteed. And if Tuchel wants to give his players another shake-up when he sees them next month for the friendlies against Uruguay and Japan, there is no better player to turn than Mainoo, who has come from out in the cold and played like he has never been away.