Roy Keane pinpointed what Manchester United were lacking in their Carabao Cup semi-final defeat to Manchester City.

The Red Devils were dumped out of the competition thanks to goals from John Stones and Fernandinho at Old Trafford.

While City progressed to a Wembley showdown against Tottenham on April 25, Ole Gunnar Solskjaer's side were left to reflect on a fourth cup semi-final defeat in just under a year.

Solskjaer spoke after the game of his frustration that United had been beaten by "simple set-plays" as they went toe-to-toe with a team he described as "the best in England".

And Keane said United had failed to seize the "big moments" in the game after Bruno Fernandes and Scott McTominay were denied early in the game.

Scott McTominay, Paul Pogba and Harry Maguire after City's first goal

"Ole mentioned there it was the moments - it is about moments," the Red Devils legend said on Sky Sports .

"Big games are about moments. United didn't quite have it tonight."

United can go top of the Premier League next week after beginning their FA Cup campaign at home to Watford this Saturday.

But Keane said their semi-final defeat showed Solskjaer's side still have some way to become serious silverware contenders.

"Again he's talking about frustration and disappointment, yeah," said Keane.

Roy Keane has disagreed with Manchester United boss Ole Gunnar Solskjaer
Roy Keane said United must make 'the biggest and hardest step'

"But you've got to move on quickly because United have a game on Saturday, then they go to Burnley - if they can win at Burnley next week they go top of the league.

"There's still positives there but it goes to show United still have a bit to go yet."

United have now been knocked out of the Carabao Cup semi-finals by City twice in the past 12 months, as well as losing at the last-four stage of the FA Cup and Europa League last season.

Keane, who won seven Premier League titles, four FA Cups and the Champions League with United, said Solskjaer's side must start turning semi-final appearances into trophy triumphs.

John Stones scores City's opener at Old Trafford on Wednesday

"Getting to semi-finals is all well and good but you got to get over the line in these big games and that's the next step to this team," said the former midfielder.

"I think they've had a lot of praise over the past few months because they've done well, they've been brilliant attacking football, they've got some momentum.

"But the next step in terms of getting to finals - and getting their hands on a trophy is their biggest step and the hardest step."

Asked how United can achieve this, Keane said big players like Fernandes must step up - blasting the midfielder after he failed to live up to recent comparisons with Eric Cantona against Pep Guardiola's side.

Keane said Bruno Fernandes 'didn't really do much' against City

Keane said: "It's not easy. Not easy winning football trophies.

"You know, Fernandes has had great praise and over the past few months people have been comparing him to Cantona etc.

"But Cantona... Fernandes didn't really do much tonight.

"The top players turn up in the big occasions. That's what the Cantonas used to do, get their hands on trophies. And that's where this team is a little bit short.

"They probably need to have one or two more players come into the squad no doubt and the mentality, maybe they need the confidence of winning a semi-final to get them over the line. Then you get momentum."