Head coach Ruben Amorim told Harry Maguire it was a "no-brainer" to activate the one-year extension in his contract at Manchester United.

Based on the centre-back's performance at the Emirates Stadium on Sunday afternoon, it was hardly surprising. He produced a colossal display to help United advance to the fourth round of the FA Cup and keep their hopes of retaining their crown alive.

Starting alongside Matthijs de Ligt and Lisandro Martinez in the back-three for the third game running, Maguire made 11 clearances, blocked five shots and produced two tackles. He was worthy of the standing ovation he received from United's supporters when he made way for Leny Yoro with 104 minutes on the clock.

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Ahead of the 2-2 draw with Liverpool just over a week ago, Amorim confirmed United planned to trigger the option to keep Maguire at Old Trafford until the summer of 2026. He said United "need him a lot", identifying him as a leader that could step forward.

Maguire has been through the mill over the last few years. From being stripped of the captaincy to being booed by some United fans in a pre-season friendly against Athletic Bilbao in Dublin, he has not had it easy.

It will be argued that criticism comes with the territory of being a professional footballer at a club like United, but Maguire found himself in a position where his every move and kick of the ball was being unnecessarily criticised and targeted.

It was not all that long ago it felt as though Maguire's only hope was to leave Old Trafford and attempt to rekindle his club career elsewhere. Now, he is one of the very first names on the teamsheet - and it is purely on merit.

The defender, 31, has made nice appearances under Amorim since he replaced Erik ten Hag at the start of November, barely putting a foot wrong. It goes without saying that Amorim's decision to change United into a team that plays with a three-man defence has been a considerable factor.

"Maguire is perfect when you play with the three defenders," said Amorim, speaking after United's 2-1 win over Manchester City last month. "I think in the middle [he] is perfect.

"Then the way that the striker that they have [Erling Haaland] with the long balls, you need to be really strong and so was perfect for him. Not just Harry, all the guys, defend really well."

Before Amorim had even arrived in Manchester it was suggested that Maguire would benefit from the three-at-the-back system the Portuguese chief was likely to use. The defender had previously excelled in a back-three for England, often linking up with the likes of Kyle Walker and John Stones.

When England reached the European Championship final in 2021, Maguire made it into the Team of the Tournament. Although the Three Lions fell short at the last hurdle, Maguire was part of a defence that conceded just two goals in the competition.

Maguire, who has started six of United's last seven domestic fixtures, has often looked more comfortable in a three-man defence, particularly in the middle of it. He is not the most mobile of players, meaning being stationed in the middle of the back-three, flanked by two defenders more comfortable on the ball, suits him down to the ground.

Operating in the middle of a three-man defence allows him to focus on his primary objective: defending. He headed and cleared almost everything that came his way at the Emirates, producing a performance that did not go unnoticed.

Maguire is not necessarily going to be a regular starter for Amorim long-term, but he has made himself an impossible figure to leave out of the starting XI at this moment in time.