In 2010-2011, Manchester United became the most successful English club of all time, winning that 19th league title.
A few months earlier, you never would have imagined the club would go on to achieve what they did, with United lying third in the league and their best player, Wayne Rooney, confirming that he wanted to leave the club. He claimed United didn't match his ambition, so he would not be signing a new deal.
Most United fans were grateful to see him change his mind and sign a contract, but by the turn of the year, Dimitar Berbatov had more hat-tricks than Rooney had goals.
When Wayne Rooney scored that fantastic overhead kick against City halfway through February, that was only his fifth league goal of the season. What is often forgotten about that goal is that it was Luis Nani who provided the inch-perfect cross for Rooney. It's also regularly overlooked that it was Nani who scored United's opening goal in that 2-1 win.
Nani was the star of the show that season and assisted more goals than anyone in the league. When looking at goals and assists combined, only Didier Drogba, with his 24 goals and assists, contributed more than Nani with 23, and he played in more games than the winger.
His team-mates voted him player of the season, despite Dimitar Berbatov being the league's top scorer, because his contribution to that title-winning season was huge. Playing on the right wing, thanks to Antonio Valencia's lengthy spell out with injury, Nani came into his own. Finally he looked like a player who could one day fill Cristiano Ronaldo's boots.
Somewhere along the way, Sir Alex Ferguson lost faith in the Portuguese winger though, and last season it looked as though there was no way back from that. In the summer of 2012, the club tried to flog him to anyone that was interested, but Nani wanted to stay. The club accepted an offer from Zenit St Petersburg but Nani demanded ridiculous wages and the deal broke down.
With Nani's contract about to expire, it was fully expected that he would leave the club in the summer of 2013. But when Ferguson retired, Nani was given a fresh opportunity to prove himself under David Moyes. Sadly, he's failed to do that.
His form has been fairly hit and miss, but too many fans have already run out of patience with him and aren't prepared to give him another go.
During United's 3-2 victory over Stoke in October, a game which United were losing until late on, Nani was audibly booed by the home fans when he was subbed off.
He hasn't played since the first week of December, and at the end of January Moyes revealed it would be a further month at least until Nani was available to play again.
The Metro reported that a January deal for the player to leave for Juventus on loan collapsed at the last minute because of worries over his fitness. It seems strange that the manager would sanction a new contract for a player only to then agree to let him leave less than 10 league appearances later.
Had Nani not had that fantastic season on the right wing a few years earlier, you might believe it's pointless keeping him at the club, but he has proven when given a regular run in his preferred position that he can be the top performer in the team.
Still, signing a lengthy deal with the club meant that Nani wasn't able to leave on a free when his contract expired, buying Moyes a bit more time. Maybe the manager has had enough time now and has made up his mind.
It's a great shame for Nani, once billed as "the next Ronaldo," that he's never shone quite as brightly as he would have liked. With him turning 28 later this year, maybe it is time for one last big move to give himself the opportunity to become the player he will have always hoped he could be.