Football London's Arsenal writer Charles Watts gives his in-depth scouting report on Sunday's visitors to St Mary's.
What grade would you give Arsenal’s season so far?
I think I would have to give it a C so far - it’s been distinctly average. At home they’ve been good, even on Saturday - when they lost at the Emirates for the first time this season - they were decent against United.
But away they’ve been really poor. They’ve lost four times on the road already this season and that’s not good enough if you want to challenge towards the top of the table.
Arsenal are fifth right now and that’s very much where they deserve to be.
What effect has the 3-1 home defeat to Manchester United had on the mood around the club?
It’s certainly killed the momentum that had been built up by the wins against Spurs and Burnley - but the general feeling after the game was that the team had played very well for most of the match.
It was just a disastrous first 10 minutes that really cost them. Conceding two goals in the manner they did left them with a mountain to club.
But to be fair to them, they played very well for the rest of the game and dominated United, unfortunately David De Gea just had one of those nights were he made save after save.
So as frustrating as the result was, it didn’t make too big a dent in terms of the morale.
Who has been the surprise package in the squad this season?
It doesn’t really feel right to label him as a surprise package because everyone knows his quality, but Aaron Ramsey has had a superb season. It’s by far and away the best he’s played since his incredible 2013/14 campaign and he’s become a hugely important player in the team once again.
He’s scoring goals, creating them and his incredible engine in the heart of midfield is driving the team on at times.
How important would a good result and good performance be at St Mary’s? What sort of a game are you expecting to see?
It would be really important given what happened against United last weekend. Arsenal had been building some good momentum before that defeat so it‘s vital they bounce back quickly with three points.
It would also be a second successive away win in the Premier League - something they have not done this season. Confidence wise it would give them a big boost going into the start of the busy festive period.
I’m sure Southampton will look to keep things tight and frustrate Arsenal, possibly look to pick them off with a set piece - which was an area of the game in which they looked very threatening against Manchester City recently.
So Arsenal have to stay switched on and patient, just as they did at St Mary’s during the win at the end of last season.
What do you think the keys to the game will be, and who will be the key men for Arsenal if they are to get a result?
Mesut Ozil has been superb in recent weeks, he has been key for Arsenal and if he can have another good game then they will fancy their chances of picking up a result.
Arsenal have to make sure they get the German into the match and give him the ball when he’s in that area between the midfield and attack where he can find Alexandre Lacazette.
In defence they have to stay switched on from set plays as well. Southampton have shown how dangerous they can be when attacking balls in and so Arsene Wenger’s side must organise themselves well when any free-kicks or corners are swung in.