Keane is notoriously hard to please, but the Sky Sports pundit even went as far as saying he felt Partey could match what his old adversary Patrick Vieira achieved at Arsenal.
Partey was at the heart of everything good about Arsenal that day and his man-of-the-match performance helped the Gunners secure their first Premier League win at Old Trafford since 2006, and their first victory away against any ‘Big Six’ rival since 2015.
“When you watch a player live, that’s when you can judge a player, and the more I look at him the more I wish he was in the United midfield,” said Keane.
“He’s big, strong and aggressive — and he can pass it forward. He can deal with the ball. I had my battles with Vieira and this kid has got a chance of matching what Patrick used to do.”
The feeling back then was that Partey had announced himself in what was only his second Premier League start after his £45million deadline-day move from Atletico Madrid last October.
But, as he prepares to return to Old Trafford on Thursday night, Partey has so far failed to live up to that early billing.
As Arsenal search for a win that will take them into the top four, now feels like an ideal moment for Partey to remind people of his talent.
Injuries have severely disrupted Partey during his time at Arsenal. The week after his fine performance against United last season, he injured his thigh against Aston Villa and, when he returned the following month against Tottenham, he lasted just 47 minutes before breaking down again.
Partey eventually returned to full fitness in January and, after playing regularly for six months, Arsenal hoped he would kick on this season. But he injured his ankle in a pre-season match against Chelsea and missed the whole of August.
When explaining why Partey has struggled, Gunners boss Mikel Arteta said: “He hasn’t had the consistency in terms of minutes and games played because of the injuries that have broken that in many, many occasions.
“Then there is the adaption to the League and you can see many examples of players that have come here and they have needed some time to do that.
“But he had a very early impact, there was that game [at Old Trafford], and then what we are looking is for him to have those top performances consistently, and to do that he needs to be fit.”
The injury against Chelsea was a particular blow to Partey because he had cut short his summer holiday to return to pre-season training early. He looked like one of the sharpest players ahead of the campaign, impressing those at Arsenal with his work ethic.
Since that injury, Partey has been doing extra sessions after training, specifically building up his leg work, as he adapts to the physical demands of English football. The 28-year-old is convinced his extra work will pay off and Arteta, too, believes there is much more to come from the midfielder.
“He is laid-back and that’s the impression that he gives, but he is very demanding of himself and he has the right experience,” said Arteta.
“He has won quite a lot already in his career and that’s what I want from him. His peak at this club is still not where it is right now.”
Old Trafford feels like the perfect stage for Partey to kick-start his season. Arsenal head there in fifth place and, although United will be boosted by the presence of new interim boss Ralf Rangnick in the stands, the Gunners are full of confidence.
They have lost just once since August and Arteta has set his sights on a statement win. Partey will be keen to make a statement of his own.