Danger for Wolves as Morgan Gibbs-White does well to evade challenges inside the box before flashing the ball across the face of goal for Serge Aurier but his shot is blocked.

Better from the hosts.

Lots of defending by Nottingham Forest so far, can they keep this up for the remainder of the half? It would be a risky strategy but Wolves are yet to threaten their goal in this half.

Clinton Morrison
Former Republic of Ireland striker on BBC Radio 5 Live sports extra

Ruben Neves hasn't started yet. It is a poor backwards header, Gibbs-White does well but a good save by Sa.

Almost a gift for Nottingham Forest!

Ruben Neves has been slow to get up to speed and his poor header back is pounced upon by Morgan Gibbs-White but his low shot is kept out by Jose Sa.

Wolves escape.

Chris Sutton
Former England striker on BBC Radio 5 Live

I can't remember many times over the last few seasons where Manchester City have been so poor. I know Pep Guardiola has made changes but we are going to have to see the big hitters come on.

Simon Stone
BBC Sport at the City Ground

Ruben Neves' introduction means that Wolves have gone to a flat back four, with Rayan Ait-Nouri pushed further forward into what seems like a bit of a floating role given he just appeared on the right, having started on the left.

See if Julen Lopetegui's plan works.

A positive start by Wolves, who do look like they are aiming to move the ball about much faster. They work it quickly down the right through Nelson Semedo but his cross is blocked.

Chris Sutton
Former England striker on BBC Radio 5 Live

What a first half from Nathan Jones' side. They started fast, they go in deservedly two goals ahead, they have been the better team.

I expect wholesale changes for Pep Guardiola and Manchester City if they want to win another League Cup.

Clinton Morrison
Former Republic of Ireland striker on BBC Radio 5 Live sports extra

That is a good sub because Wolves have struggled in the midfield.

Goncalo Guedes is the man to make way for Ruben Neves and we are back under way.

Hoods up at Forest as the rain hammers down. Wolves players are out early for the start of the second half with Ruben Neves receiving some tactical instructions before coming on.

No shots on target in that first half from City. They had 72% of the ball but didn't do much with it.

Phil McNulty
BBC Sport chief football writer at St. Mary's

What a first half from Southampton. Intensity. Aggression. Quality goals. All seemingly to the great surprise of both home and away fans alike.

Manchester City have been strictly second best here and Saints deserve their half-time lead. How long before Pep Guardiola introduces some of the heavy mob from the bench?

Image source, Getty Images

Simon Stone
BBC Sport at the City Ground

Wolves skipper Ruben Neves is going through an extensive warm-up.

The track suit top is off. He is ready to go.

The half-time whistle goes and Southampton are 45 minutes away from the EFL Cup semi-finals.

A big half-time team talk from Pep Guardiola needed.

Just one minute added on.

Sergio Gomez's cross is so powerful Ilkay Gundogan almost loses his footing controlling it with his chest. And so another move collapses before City can get a shot in.

Chris Sutton
Former England striker on BBC Radio 5 Live

Southampton seem to be more aggressive with more purpose to their play. It almost like Manchester City have turned up here tonight having beaten them at Etihad Stadium and thought it was just going to happen.

City defender Sergio Gomez is penalised for a foul throw-in. You don't see many of those given.