Meanwhile, Watford make the trip to West London knowing that victory could put the club as many as four points above the relegation zone with just five games remaining.
Having witnessed his side battle their way to victories against Aston Villa, Manchester City and Leicester City, Chelsea boss Frank Lampard would have expected more of the same against West Ham United on Wednesday evening.
However, despite dominating possession and creating the better chances, the Blues succumbed to a surprise 3-2 defeat against opponents who had struggled in their previous two outings.
The setback leaves Chelsea holding just a two-point lead over Manchester United and Wolverhampton Wanderers in the race for a Champions League spot, significantly upping the stakes ahead of welcoming Watford to Stamford Bridge.
Although Lampard will naturally be excited by the performances of Christian Pulisic in the final third, he acknowledged earlier this week that he was less than impressed with the mistakes being made at the other end of the pitch.
To a large degree, their previous wins against strong opposition are no longer relevant, and Lampard will reiterate to his players that they have to deliver a response this weekend or face the possibility of dropping down to sixth place.
Despite Watford having gone on a four-match winless streak, Nigel Pearson will feel that their extra preparation time could prove decisive at the weekend.
That will be stressed to his squad in the days leading up to this game, and it may be what they require to get themselves out of a slump which is threatening their top-flight status.
With Villa and Bournemouth looking no closer to ending their own respective runs without a win ahead of games with Liverpool and Manchester United, Pearson knows that there is a window of opportunity for his team.
For the first time since the resumption, they are clear underdogs, but being given that tag in the past has generally led to Watford delivering a positive response during a pivotal period of their season.
Chelsea Premier League form: WDWWWL
Chelsea form (all competitions): WWWWWL
Watford Premier League form: LWLDLL
Despite the defeat against Southampton, Pearson could opt against making too many alterations to his Watford side.
Although he has come through the last three games unscathed, Danny Welbeck is likely to remain among the replacements.
Chelsea possible starting lineup:
Arrizabalaga; Azpilicueta, Zouma, Christensen, Palmieri; Kante, Jorginho; Willian, Mount, Pulisic; Giroud
Watford possible starting lineup:
Foster; Femenia, Cathcart, Dawson, Masina; Hughes, Capoue; Sarr, Doucoure, Pereyra; Deeney
We say: Chelsea 2-1 Watford
With Watford having had a week to prepare for this contest, we are expecting a closely-fought match at Stamford Bridge. However, under pressure to improve after their setback in midweek, Chelsea could edge this game if Lampard freshens up his team.