It had started so well.
In August 2007, Manchester United were struggling to break down a well-organised and well-drilled Tottenham side at Old Trafford.
They had endured a slow start to the season, failing to win any of their first three games. The run included a 1-0 defeat to Manchester City, in the days when that was still considered an embarrassment.
Tottenham's visit marked Nani's first start at Old Trafford having arrived earlier that summer from Sporting Lisbon.
With more than an hour gone, it was still 0-0. But not for long.
Ryan Giggs nipped inside off the wing and tried to flick a pass through to Carlos Tevez. But it was a poor one, and Anthony Gardner cleared the danger.
As the ball broke loose, Nani nipped in between Tom Huddlestone and Paul Scholes. His first touch took it around Huddlestone. His second pushed it out of his feet.
His third was a fierce right-foot bullet from 30 yards that flew past Paul Robinson. The celebration was equally impressive, holding off Scholes to somersault in front of the Stretford End.
United won 1-0. And by the end of the season they were Premier League champions and Champions League winners.
But fast-forward seven years and Nani is on his way back to Portugal, his United career having never reached the heights promised with that flash of brilliance against Tottenham.
It's not that Nani was a flop.
It's just, well, it's just he was never as good as he should have been. And that's the feeling that will nag United fans as the Portuguese winger heads home.
Watching Nani became like buying a scratch card. You know you shouldn't get excited. You know, deep down, that you're not going to win. That he was probably going to give the ball away or attempt a cross that ended up in the stands.
But there was always that hope that you might reveal the £1 million. That he might take two touches and score from 30 yards.
It seems strange to say now but, at one time, there was a genuine hope he might follow Cristiano Ronaldo's career trajectory.
Both Portuguese. Both signed from Sporting Lisbon. Both comfortable on either foot, blessed with pace and trickery.
But Nani never made the step up from useful squad player to superstar. Ronaldo did and became one of the best players in the world.
Whether Nani could have ever hoisted himself to that level, we'll probably never know. He wasn't helped by injury, especially in the last two years, or that undeserved red card against Real Madrid.
But only he will know whether he could have worked harder or trained longer; whether his attitude was right during every training session and every game.
The manner in which his United career ended this week is proof of how far he's fallen since that day at Old Trafford in 2007.
He promised so much more than to return home as a makeweight in a deal for a mid-priced Argentinian defender, as per the Manchester Evening News. Whether United fans are glad to see him go or not, it's a sad end.
There will, or course, always be the memories.
His goal against Chelsea in the 2009 Community Shield. His run and finish against Bolton in 2010. His successful penalty in the 2008 Champions League final.
But they are all highlights. Flashes. Not sustained spells of quality.
And that's the reason, at only 27, he'll probably never play for United again.
It's a sad end to a United career that once promised so much.