Chelsea have put together a 10-match unbeaten streak in all competitions, but Maurizio Sarri will be keen to register a first league win in three attempts after draws with West Ham United and Liverpool.
Southampton's performances have generally improved since the arrival of Mark Hughes earlier this year, but the Welshman still has plenty of work to do when it comes to his team being able to see out matches.
Hughes has watched his side lose five points during the last 15 minutes of Premier League fixtures this season, including at Molineux last weekend as the Saints held their own against in-form Wolverhampton Wanderers.
The West Midlands outfit netted twice in the closing 11 minutes to condemn Southampton to a result which has left the club sitting in 16th position in the top-flight standings.
The mood at the club naturally improved courtesy of the penalty-shootout triumph at Everton in the EFL Cup, but Southampton again conceded a late goal which undermined their efforts throughout the match.
Ironically, Southampton's only two wins in all competitions this season have been partly due to goals scored after the 88th minute, but Hughes needs to find a way to ensure that his squad are learning from their issues at the back.
Danny Ings has been excellent since arriving at St Mary's from Liverpool, with the Englishman netting four times in six starts and one substitute outing in all competitions.
Southampton are underdogs to claim a result against Chelsea this weekend but with the derby against Bournemouth and a crucial home fixture with Newcastle United to come after the international break, any positive result will help ease the pressure heading into that double-header.
Recent form: LLWDLL
Recent form (all competitions): WWDLLD
Chelsea have only scored five goals in their last five games in all competitions, but their struggles in front of goal have not taken away from the positive mood which has been created since the arrival of Maurizio Sarri.
The club's supporters have generally accepted that the Italian has introduced a more attractive style of play, and a period of 10 games without defeat is not going to generate too much negativity in the stands.
Nevertheless, Chelsea remain far from the finished article and will not become that until either Olivier Giroud or Alvaro Morata are able to provide the return expected of them in and around the penalty area.
Giroud only has three assists to show for his 299 minutes on the pitch this season, while Morata has found the back of the net on just two occasions in 10 appearances
Sarri will hope that Morata's decisive goal in Thursday's Europa League fixture with Videoton will lift his confidence, but the Spaniard requires an extended scoring streak if he is going to win over the supporters.
Chelsea have improved in defensive areas of the pitch, with only a wonder strike from Daniel Sturridge denying the West Londoners a clean sheet against Liverpool last weekend, but Sarri's side have only conceded one goal or fewer in a match as many as nine times from 11 attempts since the start of the campaign.
The team will only continue on an upward curve while that remains the case, but Sarri has already spoken about having to manage the workload of his players in order to challenge in all four competitions.
We are yet to see how Chelsea will cope when being forced to make a number of changes to a starting lineup which appears set in stone from front to back but for now at least, a chance to reach the second international break without defeat in the Premier League will only convince everyone associated with the club that they can mount a challenge for the title.
Recent form: WWWWDD
Recent form (all competitions): WWDWDW
Sarri is likely to revert to the team which began the game against Liverpool last weekend, meaning that Giroud should get the nod over Morata.
Hughes has revealed that both Mohamed Elyounoussi and Long are back in contention after sitting out the game against Everton.
Southampton possible starting lineup:
McCarthy; Soares, Vestergaard, Hoedt, Bertrand; Lemina, Hojbjerg; Elyounoussi, Ings, Redmond; Austin
Chelsea possible starting lineup:
Arrizabalaga; Azpilicueta, Rudiger, Luiz, Alonso; Jorginho, Kovacic; Willian, Kante, Hazard; Giroud
Head To Head
Sunday's meeting will represent the 103rd competitive encounter between the two clubs, with Chelsea registering 44 wins in comparison to 30 victories for Southampton.
The Saints went through a period where they were regularly upsetting the Blues, with two wins and three draws coming from seven matches between 2013 and 2015.
However, Chelsea have prevailed in each of the last six fixtures, with the most recent triumph coming in the FA Cup semi-finals in April.
We say: Southampton 1-2 Chelsea
Chelsea may be unbeaten since losing to Manchester City in the Community Shield, but they continue to struggle to take their chances in the final third. That could keep Southampton in the game at St Mary's, but the visitors should still have enough to secure three points on the south coast.