Where Southampton vs Manchester City will be won and lost this weekend

With Chelsea streaking away into the distance already, this weekend sees a meeting between their two closest challengers. Whoever wins in Sunday’s fixture between Southampton and Manchester City will end the day in second place – although Jose Mourinho’s side will surely see this as an opportunity to extend their lead further.

Here are three key battles ahead of the fixture at St Mary’s…

Sergio Aguero vs Saints' high line

Southampton don’t press as intensely under Ronald Koeman as they did under Mauricio Pochettino, but their defensive line still takes up a position close to the halfway line when possible.

The backline is extremely disciplined, however, and a combination of the aggressive approach to controlling space, and the cohesion when the back four steps up, means Southampton have caught the opposition offside more frequently than any other team in the division.

However, if there’s one player you don’t want to face with a high defensive line, it’s Sergio Aguero. The Argentine is currently playing the best football of his Manchester City career, and loves racing in behind the opposition.

What’s particularly interesting is the slight change in his role. Whereas previously Aguero played in conjunction with Edin Dzeko, making his runs from a deeper position, his best performances this season have come when he’s been fielded high up the pitch, essentially as a lone striker.

He hit four goals against Tottenham Hotspur when playing there, and followed it up with a hat-trick against Bayern Munich in midweek. Against Spurs, he never came short in central positions, simply worked the channels and then charged into the box.

How Southampton elect to deal with Aguero remains to be seen – logically you’d expect them to play deeper, though Koeman will be reluctant to meddle too much with an approach which has produced the best defensive record in the division. Therfore, Southampton’s press in advanced positions must be good, to prevent through-balls reaching the Argentine.

Southampton’s third man v City’s defensive destroyer

Southampton have played a fluid style of football this season, meaning that in possession it’s often difficult to tell whether Koeman has deployed a 4-3-3 or a 4-2-3-1.

Morgan Schneiderlin is a surefire starter, with two of Victor Wanyama, Steven Davis and Jack Cork also playing. Cork or Davis have usually played the advanced midfield position, and rotate regularly with their midfield colleagues.

For Monday night’s trip to Aston Villa, however, Koeman tried something different. Davis, excellent so far this season, was out injured, and Koeman knew Villa had major injury problems at centre-back.

Therefore, he changed his system slightly, using only Schneiderlin and Wanyama in midfield, and bringing Shane Long into the side to support Graziano Pelle to put maximum pressure on the Villa defence.

Long and Dusan Tadic switched positions midway through the game, bringing a different shape to Southampton’s play, but it made relatively little difference to the build-up. Southampton were unusually sluggish when working the ball forward, with no link between midfield and attack.

Schneiderlin and Wanyama aren’t the most creative players, and missed Cork’s intelligent but patient passing, or Davis’s forward running. Tadic is better at providing the key passes, rather than linking play.

Therefore, Koeman’s key decision is about the third player to field in his midfield zone – Davis will surely return if fit and will charge forward into attack, although the value of Cork’s distribution shouldn’t be underestimated either.

This is a crucial zone, because Manchester City haven’t looked entirely comfortable deep in midfield this season. Fernando and Fernandinho have started the season sluggishly, Yaya Toure has been off-form and doesn’t contribute much without the ball, while Frank Lampard has performed well as a substitute, but has struggled against high-tempo opposition when starting matches.

Joe Hart v Fraser Forster

They won’t be in direct combat throughout this game – well, not unless City are losing in the final minutes and Joe Hart darts upfield for a corner – but this game is a clash between England’s first-choice goalkeeper and the man now considered his No.2, Fraser Forster.

Hart’s form has been dodgy for around 18 months now, and he had another difficult midweek against Bayern. There were no glaring errors, but he was made to look foolish for both Bayern goals – first Xabi Alonso neatly despatched a free-kick into the bottom corner with Hart rooted to his goalline, and then he was beaten by Robert Lewandowski’s miscued header, which deflected off the Pole’s shoulder, and in off the post.

Goalkeeping errors tend to be viewed in terms of fumbles and spills – Simon Mignolet is receiving plenty of criticism for that reason – but it’s a more significant problem when a goalkeeper’s positioning is questioned. Hart once appeared an extremely calm and composed goalkeeper but increasingly seems to be making poor decisions, and he could do without his understudy overshadowing him this weekend.

Forster also made an error this midweek, though. Southampton went 1-0 down at Aston Villa when Forster darted forward from his goalline, but failed to intercept a long ball, and allowed Gabriel Agbonlahor to nip in and score. It was particularly obvious considering Forster didn’t have anything else to do all game – that was Villa’s only shot on target.

Sweeping is vital for a keeper when playing behind a high defensive line, and it will be interesting to see whether Forster’s decision-making changes after that error. Against Aguero, this could be crucial.

Southampton vs Man City LIVE ANALYSIS with Stats Zone