Chelsea and Manchester United meet in a heavyweight Carabao Cup clash at Stamford Bridge on Wednesday (streaming on ESPN+, 3:55 p.m. ET) that will end with one of England's biggest clubs having a route to silverware closed off less than three months into the season. The two teams are both in a period of transition under the management of legendary former players in Frank Lampard (Chelsea) and Ole Gunnar Solskjaer (United), but progression in the Carabao Cup will keep alive the prospects of a trophy this term.

Much has changed for both clubs since United recorded a 4-0 win over Chelsea at Old Trafford on the opening weekend of the season, so how does this game stack up, and where will it be won and lost?

What has changed since that 4-0 result at Old Trafford?

Back on Aug 11, United made a dream start to the season by hitting four past Chelsea, but the victory proved to be a flash in the pan for Solskjaer's team. United have since struggled for goals and form, with Sunday's 3-1 win at Norwich the first time they've scored more than once in a game since that opening weekend.

Injuries to key players like Paul Pogba, who is out until December, and the fit-again Anthony Martial have held United back, but their squad remains worryingly thin, meaning that several first-team players will have to play at Stamford Bridge when they would ordinarily be given a midweek off.

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Chelsea have bounced back strongly from that defeat at United, with Lampard lifting his team into the top four and guiding them to two wins out of three in their Champions League group.

With Chelsea under a transfer ban, Lampard has had to give youth a chance and he has been rewarded with some outstanding performances from Mason Mount, Fikayo Tomori, Callum Hudson-Odoi and, most recently, Christian Pulisic.

The success of Chelsea's start under Lampard is that nobody is talking about Eden Hazard. The Real Madrid forward was obviously a big loss when he left in the summer but Chelsea have moved on impressively.

Who needs the win the most?

There's no straightforward answer to this one. If you are Chelsea or Manchester United, the expectation is to challenge and/or win every competition you enter and they will both regard the Carabao Cup as a chance to bag some silverware this season. The better question is probably centred on who would feel a defeat most painfully: The answer to that is Solskjaer.

Chelsea are in the top four and the Champions League, so their season is going to plan. In fact, many would argue that they are exceeding expectations. But Solskjaer is battling to revive United and he needs every break he can get right now, so elimination at this stage of the Carabao Cup would be a big blow.

Chelsea and Lampard could still look at the positives of this season if they go out, but United need a cup run to boost morale, on and off the pitch.

Which club has the best kids?

Chelsea and United have put their faith in youth this season, albeit for different reasons, but both clubs are reaping the rewards of that approach.

Thanks to a two-window transfer ban for breaching regulations over the signing of foreign U18 players, Lampard has been forced to hand opportunities to Mount, Hudson-Odoi and Tomori, and all have taken their chance.

At United, Solskjaer has offloaded the likes of Romelu Lukaku, Alexis Sanchez, Ander Herrera, Antonio Valencia and Marouane Fellaini this year in order to give the club's home-grown youngsters, such as Scott McTominay, Mason Greenwood, Axel Tuanzebe, James Garner and Brandon Williams a run in the first-team.

Chelsea's youngsters are older and more experienced, so they have the edge right now, but both clubs are laying the foundations for future teams by giving the kids a chance.

Who are the key men in this game?

Much depends on the strength of the two sides, with Chelsea's squad deeper than United's, who may be restricted from too many changes by injuries to first-team players. But after scoring a hat trick at Burnley at the weekend, Pulisic will hope to be handed another start by Lampard in order to build on his goalscoring form after a difficult start to life at Stamford Bridge.

Solskjaer may rest £85 million centre-half Harry Maguire and give a rare start to Phil Jones, but United's strengths are up front, where Martial and Marcus Rashford will look to develop their attacking partnership in this game.

Who wins?

United have a poor record at Stamford Bridge, with their FA Cup third-round victory last season only their third win at Chelsea this century.

While United will be buoyed by that 2-0 triumph last term, Chelsea's recovery from the opening day loss at Old Trafford makes them favourites heading into the game. But having ended their 11-game winless streak away from home with a 1-0 Europa League win against Partizan Belgrade in Serbia last Thursday, United backed it up with Sunday's 3-1 victory at Norwich.

This one is too close to call, so it may even go to penalties at the end of 90 minutes.