The FourFourTwo Preview: Chelsea vs Southampton
Mauricio Pochettino's side have made a superb start to the season, with just two losses from their opening 12 matches, leaving them in fifth place.
They saw an unbeaten eight-game streak in the Premier League brought to an end by Arsenal last weekend, as an error from goalkeeper Artur Boruc contributed to a 2-0 defeat.
The Poland international failed to deal with a routine back pass from Nathaniel Clyne, mis-controlling the ball to allow Olivier Giroud to rob him of possession and easily fire the hosts ahead after 22 minutes.
Frenchman Giroud then scored again shortly before full-time - netting his seventh goal in 12 league games courtesy of a penalty after Jose Fonte was adjudged to have pulled Per Mertesacker's shirt.
Pochettino's men will now look to bounce back and start another unbeaten sequence, although they will be underdogs against a Chelsea side stung by a late goal from Mohamed Salah that sent them to defeat against Basel in Tuesday's UEFA Champions League clash.
The 21-year-old's effort capped a disappointing performance in Switzerland for Jose Mourinho's side, with an injury to striker Samuel Eto'o compounding their misery.
Eto'o has now been ruled out of Sunday's clash with a muscle strain, while Brazil defender David Luiz is back in training after his knee injury but will not be risked.
The visitors have injury concerns of their own, after defender Luke Shaw was forced off at half-time at the Emirates Stadium after sustaining a knock.
Pochettino will, though, hope to welcome back defender Dejan Lovren, after he missed the Arsenal game with a sickness bug.
The match is likely to come too soon for Jack Cork, who has a twisted ankle.