Alex Ferguson forms part of a select crew of managers who have won the European Cup more than once, having famously led Manchester United to the crown in 1999 and 2008.
However, given the great manager's esteemed career and success at domestic level, it remains something of a surprise that his Manchester United teams did not manage to win more than the two European Cups they claimed during his reign.
There were near misses, most notably trips to the final in 2009 and 2011 in which they came up short against Barcelona, and other occasions on which United and Ferguson could count themselves somewhat unfortunate not to progress deeper into the tournament.
One of those occasions - in Ferguson's mind at least - was the blockbuster 2013 Champions League last 16 clash with Real Madrid.
Having signed Robin van Persie the previous summer, United were in control of the Premier League, and looked like one of the favourites to ultimately take Champions League glory.
One crucial decision in the second-leg, however, swung the match in Real's favour. In his autobiography, Alex Ferguson explained just how distraught he was by what he saw as an unjust decision.
Alex Ferguson: Manager felt referee cost Manchester United 2013 Champions League
After a 1-1 draw in the first-leg in Madrid, Manchester United welcomed Real to Old Trafford in March 2013 leading on away goals. A Sergio Ramos own goal early in the second half put Ferguson's team on the verge of qualification, before a contentious red card for winger Nani left United down to ten men.
8 years ago today, Nani was sent off against Real Madrid.
One of the biggest injustices in recent football. I'm still angry.#mufc🔴 pic.twitter.com/5cFCPGjKet
— UnitedsRelated (@UnitedsRelated) March 5, 2021
Nani was sent off by Turkish referee Cuneyt Cakir after meeting Álvaro Arbeloa with his raised right foot while attempting to claim an Antonio Valencia clearance.
The red card proved contentious. Though Nani did make contact with Arbeloa's chest with his foot, it was with minimal force, and was certainly not intentional given his eyes were facing the other direction prior to the contact. By the letter of the law, it was a red card, but it was certainly one which felt quite harsh on the Portuguese winger.
In his 2013 autobiography - written shortly after his retirement - Alex Ferguson said he would have been intrigued to hear from the match referee in a post-match press conference:
I would have found it interesting to hear from the Turkish referee who handled our Champions League tie against Real Madrid at Old Trafford in March 2013, and listen to what he had to say about Nani's sending-off, which was appalling.
I've lost two important European ties to José Mourinho, not because of the performance of the players but because of the referee.
The game against Real Madrid would prove to be the last European game Ferguson ever managed, with the legendary manager deciding to retire after claiming a 13th Premier League title at the end of that season.
It would have hurt even more, then, to be eliminated after what was seen as an unjust red card, against a manager with whom Ferguson shared a fantastic rivalry in José Mourinho. Even more painful was the fact that Real Madrid's winning goal was scored by United legend Cristiano Ronaldo, who had burst onto the global scene after being nurtured as a young player by Ferguson.
Five years ago, Cristiano Ronaldo knocked Manchester United out of the #UCL 🌟
Will Juventus’ main man find the net against his old club tonight? 🔛 🔜
@FTBSantander #POTW pic.twitter.com/RkMXY5LTID
— UEFA Champions League (@ChampionsLeague) November 7, 2018
The 2013 Champions League was notoriously open, with the likes of Malaga and a then-not-so-ominous PSG reaching the last eight. Had United beaten Real, they would have faced Galatasaray in the quarter-finals, before Borussia Dortmund in the semi-finals.
Ferguson believes that referee Cakir robbed his side of a shot at a third Champions League crown with his "ludicrous" decision to send Nani off and reduce United to ten men:
Nani was sent off in the 56th minute for leaping to meet the ball and making slight contact with Álvaro Arbeloa, and for ten minutes we were up against it. We were in shock. On came Modric for Real to equalise Sergio Ramos' own goal and then Ronaldo finished us in the 69th minute. But we might have scored five in the last ten minutes. It was an absolute disaster.
I was particularly upset that night and gave the post-match press conference a miss. If we had beaten Real Madrid, there would have been every reason to imagine we could win the competition.
After the Old Trafford game, as I was watching the video of the sending-off, Ronaldo came in to sympathise. The Real players knew the sending off had been absurd. Mesut Ozil confessed to one of our players that José's team felt they had got out of jail. Cristiano declined to celebrate his goal, which is just as well, because I would have strangled him.
The fact that even the Real Madrid players allegedly agreed that the decision was harsh, despite the clattering contact from Nani, gives a fascinating insight into the mood around Old Trafford that night.
It was a sad way for Alex Ferguson's European journey to end, and one of the great "what ifs" of a truly great career.