Liverpool, Arsenal and Newcastle are through.

But who will be joining them in the semi-finals of the League Cup - Tottenham or Manchester United?

Catch you back here tomorrow to find out.

Image source, Getty Images

Image source, Getty Images

Image source, Getty Images

Brentford

Brentford boss Thomas Frank, speaking to BBC Radio 5 Live: "It sounds a bit crazy maybe but beside the two goals in the first half they had nothing. In these cup games you need to try to stay in the tie and hopefully be better in the second half, but we gave two bad goals away and then the third one too.

"Our goal for 3-1 was a beautiful goal, so now imagine if it was only 2-1. The pressure builds in the last four or five minutes and you never know what can happen. That is the irritating part but it is what it is. "

Arsenal

Arsenal forward Gabriel Jesus, speaking to BBC Radio 5 Live: "I wear the number nine for Arsenal so I have to be scoring goals, Kai [Havertz] as well, we are the strikers of the team and have a pressure to score.

"If you want to challenge for a place we have to keep scoring. It is not easy, if it was then there would be many strikers in the world, but we keep trying.

"I am happy with the goals but I am more happy with the win because we are in the semi-final. A lot of people don't watch the games and only look at the stats after and who scores. Maybe we win 1-0 and I do a good action but do not score and we win.

"I came here to win the Premier League and my first two seasons we were there but for some details. This third season I want to win."

Crystal Palace

Crystal Palace boss Oliver Glasner: "It was the perfect start but already in the first half we looked like we played with too much respect, a little bit too cautious. Especially in possession.

"We need a performance of our top level and it was not a performance at our top level. It was positive that we scored two goals, but at the end it is a little bit frustrating because if you score two at the Emirates then it should have been a penalty shootout at least."

On Arsenal's second goal: "I think it was offside but there is no VAR. Everyone knows this. They had too many chances in the second half, we gave them too many chances. When they found the gaps we shifted too slow."

Chris Waddle
Former Newcastle & England winger on BBC Radio 5 Live

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The win will give Newcastle a lot of confidence, particularly if they can put a nice run together going into the semi-finals.

When Newcastle were challenging for the top four they were all about creating lots of chances and scoring goals and building that confidence. It seems to be coming back now.

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Arsenal boss Mikel Arteta on hat-trick hero Gabriel Jesus: "It's now about consistency. It's a moment of spark that will bring so much to the team that we can rely on him to change games. We need to give him more chances."

Liverpool

Liverpool manager Arne Slot, speaking to Sky Sports: "We have to defend the trophy because the club won it last season. I wasn't involved in it, but the players were and of course, Jurgen [Klopp] was with his staff. As a club we want to compete for all trophies. But we are also aware of Arsenal, Newcastle, Tottenham and Manchester United. It's a tough competition for sure."

Arsenal

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Arsenal's hat-trick hero Gabriel Jesus, speaking to Sky Sports: "I have scored a lot of goals but sometimes I have this problem with a lack of goals.

“I can create, I can make assist, I can run and help the team defending. When I score everyone sees, but when I don’t they want their striker to score goals and I agree with that.

“That is why I am working a lot in training, finishing more, putting myself in a good position to finish the action.

“I think my hard work has paid off.”

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Arne Slot had to rough it in the press box at St Mary's as he served a touchline ban. At least tomorrow's back pages will make good reading for the Liverpool boss and his players.

"You have a very good view of the game than when you are down in the dugout," Slot told Sky Sports afterwards.

"But sometimes it is also difficult if you want to influence the players.

"But I have very good staff, so even when I wasn't around, they were able to get the game over the line."

Liverpool

Liverpool boss Arne Slot, speaking to BBC Radio 5 Live: "It wasn't easy circumstances to play in because of the wind of course, but it was a very good and important win for our team. We saw a lot of players that maybe don't start, we saw a lot of players that have had an impact already, so for us to have these players playing games is important.

"It doesn't matter too much what your back line is if you have the ball as much as we did in the first half. Then you have control. Second half the control was not there as much so your defenders are exposed, especially if they are not defenders.

"We handled it really well and only conceded one or two chances. The second half wasn't as good as the first but it was enough in the end to bring the win over the line."

Francis Benali
Former Southampton defender on BBC Radio 5 Sports Extra

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Southampton were pretty non-existent in the first half where they had to better in many, many ways.

But it was understandable in the circumstances they find themselves in, with Simon Rusk having little time with the team after the departure of Russell Martin.

But they were much better in the second half. They need to look back on what they did well in that second half to try to move forward during the rest of the Premier League season.

Chris Waddle
Former Newcastle & England winger on BBC Radio 5 Live

Newcastle haven't had a holding midfielder for a while now.

Under Eddie Howe they have tended to play three midfielders who all get attracted to the ball and want to go and follow it and create, and I feel for the centre halves because they get exposed a lot.

With Sandro Tonali coming back in he plays in front of the back four and it is a good position for him.

Liverpool

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Liverpool's Tyler Morton, speaking to Sky Sports: "It was a tough test for us, especially with a lot of young lads coming in. Everyone who played today was ready and the gaffer chose a different side. It was tough for us at the start, but we gained control early on, which gave us a lot of confidence.

"Playing at this club in front of these fans, they give us a lot of confidence. Even when you are down, you have a feeling that you can come back. The energy that they give us is what we love as a team. It was a tough fight for us today right until the end."

Brentford

Brentford boss Thomas Frank told Sky Sports: "We lost on the day to a better team. We can't concede three goals. That's the bit I'm very disappointed with.

"We have to sort that out. In a difficult quarter-final we can't concede three soft goals. Fair play to Newcastle, some were well worked. But if we want to progress to semi-finals we need to do better."

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Matt: We lost, but what a better second half after being poor in the first half. Great sound in St Mary's tonight! Something to build upon? We have fight and we can compete at this level!

Newcastle United

Newcastle boss Eddie Howe speaking to BBC Radio 5 Live: "Really pleased. It was a good performance from the players. Every game brings a new challenge and Brentford were what we thought we would be, a strong team.

"I thought we scored some really good goals. It was great to see Sandro [Tonali] score the two that he did. Just a really good feeling about the group at the moment. We are building in confidence all the time.

"We are starting to see the best of him [Tonali]. The tweak in position has definitely helped him, he is a lot more comfortable when he is deeper on the pitch. He is showing all the qualities that we knew when we signed him. It is just about finding the right balance for him and the team.

"The midfield wins and loses you games, it goes without saying that it is such an important area of the pitch. It was good to see him [Tonali], Bruno [Guimaraes], Joelinton and Joe Willock all playing well today.

"The balance of the team is good. We have players playing in their chosen positions and playing well. We look creative again and a high number of shots and chances to score.

"Disappointed with the bookings and to lose two key players in Bruno and Schar [for the semi-final] but it goes with the territory. We are competitive and encourage the intensity so you can't have everything."

Chris Waddle
Former Newcastle & England winger on BBC Radio 5 Live

Image source, Getty Images

Quite an easy night for Newcastle. They won't play an easier quarter-final tie.

Last 10-15 minutes Brentford had a go, came to life when they made substitutions and brought on the 'A' team. For me they should have done that from the start.

Liverpool

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Liverpool's Harvey Elliott ,speaking to Sky Sports: "We came into this game knowing the circumstances that Southampton were going through and knew they were going to come out fighting and we were ready for it.

"Some of us hadn't played so much this season. We also had really young lads in the team. But we fought as team and thankfully we came away with a win."

On Southampton's performance: "I wouldn't say I was surprised by it because if you look at the Premier League, they caused problems for us as well. They are a side full of confidence and they are not scared to play out from the back and take risks. Credit to them, they caused problems for us today.

"We had to make sure we stood strong and defended as well as we can as a team. And despite conceding one goal, we did that really well."

Southampton

Will interim boss Simon Rusk still be in charge of Southampton when they go to Fulham on Sunday (14:00 GMT)?

They're nine points from safety at the bottom of the Premier League.

But that was much, much better by Saints in the second half.