What has the manager said?
Ralph Hasenhuttl has promised Southampton will sign new players in the January transfer window.
When asked how important the window is to his side, Hasenhuttl replied: "Absolutely important. We must see that we get some new players in. We know this. The summer window was not perfect for us.
"It is absolutely clear that we must do something with the full-back positions. This is definitely a position we're looking at for the moment and we will do something.
"The problem is the (transfer) fee for Premier League clubs is always very high. We will try to bring two guys in.
"We have enough quality to score, we score nearly always, but the defence is definitely something we must improve and do something in the transfer market.
"We had issues in the summer - the balance of the team is not 100 per cent what it should be. We have a few positions where we have a lot of alternatives and other positions, we don't have any. This is not healthy when we have suspensions or injuries."
What did Southampton do in the summer?
Southampton spent £15m apiece on Che Adams and Moussa Djenepo from Birmingham and Standard Liege respectively, while Danny Ings completed a permanent move from Liverpool after his loan spell in the 2018/19 season.
Matt Targett departed for Aston Villa for £11m, while Charlie Austin, Sam Gallagher and Jordy Clasie also left for undisclosed fees.
Steven Davis signed for Rangers on a free transfer, and Fraser Forster and Mohamed Elyounoussi joined their Old Firm rivals Celtic on loan.
Mario Lemina and Wesley Hoedt also left on loan to Galatasaray and Royal Antwerp respectively after the domestic window had closed.
Who have they been linked with?
Aaron Long, New York Red Bulls [Sky Sports News]; Joakim Maehle, Genk [Sky Sports News]; Jarrod Bowen, Hull City [The Daily Mirror]; Adrien Tameze, Nice [Daily Telegraph].
Who could depart?
Jannik Vestergaard [Sunday Mirror]; Che Adams, Leeds [Leeds Live]
Analysis: What to expect this January
Sky Sports News' reporter Lyall Thomas...
"Southampton want to strengthen defensively with a new centre-back and right-back if they can in January.
"With the contracts of Cedric Soares, Maya Yoshida and Shane Long expiring at the end of the season, these players could leave the club next month.
"Among their targets at right-back is understood to be Genk's Denmark international Joackim Mahle, while they were interested in RB Salzburg centre-back Mario Pongracic in the summer."
How to follow the January transfer window with Sky Sports
Sky Sports will bring you the very latest news from the January transfer market with the return of three shows.
Start your day with Good Morning Transfers at 9am as our team of reporters bring you the latest news and insight. Transfer Talk then follows at midday delivering analysis of the biggest stories. Then join us at 7pm for the definitive round-up of the day's news with The Transfer Show.
Meanwhile, the Transfer Talk podcast will also be back at the turn of the year with more expert analysis from here and across the continent.
And as well as tuning into Sky Sports News, don't miss a thing with our dedicated Transfer Centre blog.