September 27, 2014, is a date Paddy McNair is unlikely to ever forget.

At the age of just 19, the Northern Irishman was awarded his Manchester United debut by Louis van Gaal, tasked with stepping into the heart of the back-four amid an ongoing injury crisis.

Two days before the visit of West Ham United to Old Trafford, Van Gaal, hosting his pre-match press conference, confirmed United were incredibly thin at centre-back, naming Marcos Rojo as the only senior option who would be fit for the visit of the Londoners.

“All three of my right-sided centre-halves are out, so I’ll have to go to the youth system,” said the former United manager.

Turn to the youth ranks he did, selecting McNair ahead of Tom Thorpe, who was named on the bench, to start alongside Rojo. McNair’s only previous first-team experience had come when he was named on the bench for the infamous 4-0 League Cup defeat to MK Dons a few weeks earlier.

Helping United, who had Wayne Rooney sent-off, secure a 2-1 win, McNair kept his place in the team for the subsequent Premier League fixture, starting another 2-1 triumph, helping the Reds get the better of Everton the following weekend.

However, McNair’s run in the team was halted by an injury of his own. He did reclaim his place after missing two league games and then stepping off the bench in a 1-0 defeat to Manchester City, starting victories over Crystal Palace (1-0) and Arsenal (2-1).

As the 2014/15 season unfolded, McNair found himself in and out of the team, ending the campaign with 18 appearances to his name. It was a respectable figure for an academy graduate in his breakthrough season at Old Trafford.

Having developed a taste for first-team football for the first time in 2014/15, McNair’s hunger for senior football grew. However, the return of key players meant opportunities were not as forthcoming the following campaign, with the 2015/16 season yielding just nine first-team appearances.

A decrease in minutes meant McNair, who is currently on loan at Championship side West Bromwich Albion from US outfit San Diego, pushed for an exit in the summer of 2016. Jose Mourinho had been appointed as Louis van Gaal’s successor and he strengthened the club’s centre-back options with the capture of Eric Bailly.

United, mindful that McNair had done well when presented with opportunities by Van Gaal, wanted to take his development up a notch and send him out on loan for the first time in his career. The club felt securing regular first-team football was what the Northern Irishman needed next in his long-term quest to become a regular fixture at Old Trafford.

However, a temporary loan move elsewhere wasn’t something McNair wanted to entertain; he wanted to leave permanently instead. It was a decision that led him to pleading with Mourinho to alter his transfer plans.

McNair explained: “He wanted me to go on loan and I went in to see Jose and just said ‘look, if you don’t let me go on a permanent, I’m just going to stay here’.

“That’s how strongly I thought about it. At the time, it’s what I wanted so I’ve got no regrets. I think he quite liked how I was straight up. I said I wanted to leave, that I didn’t want to go on loan.

“I think he respected that. I told him that I’d been here since I was 12-years-old and club could at least let me do what I want to do.”

McNair, who is now 29, also approached former executive vice-chairman Ed Woodward in his pursuit to leave Old Trafford on a permanent basis.

“I spoke to Ed Woodward and said the same to him,” McNair added. “I was refusing to go on loan basically. I just wanted a new challenge and off I went.”

Three days before United’s Premier League opener in August 2016, McNair got his wish, sealing a move to Sunderland, who were still in the Premier League at the time. He joined the Black Cats alongside fellow United youngster Donald Love in a deal worth £5.5million.

McNair’s move to the Stadium of Light enabled him to try and stamp his authority on the first-team with the intention of becoming a regular. However, just 12 appearances into his Sunderland career, he suffered an ACL injury and missed the remainder of the season, meaning he was unable to help the Black Cats’ in their unsuccessful fight against relegation.

It was not until late-October in 2017 that he returned. Opportunities remained limited but he did manage to chip in with five goals in 16 Championship appearances from a defensive-midfield role.

McNair, who was compared to Michael Carrick by former United youth coach Paul McGuinness as a youngster, left Sunderland the following summer, moving to Middlesbrough. He spent six years at the Riverside, making 219 appearances, before leaving at the end of last season.

Although he ended up working with Carrick at Boro, it was at centre-back where he racked up a large percentage of his appearances. Nevertheless, he was a stalwart figure on Teesside for several years.