Samuel Eto'o was the hero of the hour on Sunday, hitting his first hat-trick for the club to ensure they remain well positioned in the title race.
Indeed, he was the talk of Stamford Bridge as fans emptied out of the stadium come the final whistle—some even labelling him a god when they gave their reactions to Bleacher Report in the immediate aftermath (watch the video here).
Come Monday morning, however, there would have been a somewhat different mood among supporters when the realisation struck that Fernando Torres is expected to be sidelined for at least a month, as reported by BBC Sport.
If that proves to be the case, he will most certainly miss vital fixtures against West Ham United, Stoke City in the FA Cup, Newcastle United and West Bromwich Albion. Sandwiched between those matches will be Chelsea's trip to the Etihad Stadium to face Manchester City on Feb. 3.
It's not so much a crisis just yet, especially when Eto'o's three goals against United suggests he may well have finally settled into life in the Premier League.
Torres' injury does highlight the frailties in Chelsea's front line, though.
With the Spaniard crocked, Mourinho now must pick from Eto'o and Demba Ba to lead Chelsea's title push. It's not nearly enough when considering Manchester City have Sergio Aguero back to full fitness and scoring goals alongside Alvaro Negredo and Edin Dzeko.
Manuel Pellegrini has an embarrassment of riches at his disposal, while Arsene Wenger himself isn't too short on forward talent with Lukas Podolski, Olivier Giroud and Nicklas Bendtner all capable of seeing Arsenal through the remaining months of the campaign.
The short-term solution for Chelsea would be to splash the cash in January, bringing in a striker capable of getting them through what remains of 2013-14 while Torres is injured.
It would be just that, though—short term. Unless it was a striker in the class of Wayne Rooney or Diego Costa, it would serve very little and beyond this term could prove a bigger problem than that of Torres' current injury woes.
The rhetoric coming out of Stamford Bridge this season has been of a "project," with Mourinho himself playing down his team's chances of Premier League success. Chelsea these days are focused more on the long term, and their policy suggests they are willing to sacrifice the present to secure their future.
So why allow Romelu Lukaku to leave on loan for Everton? If Chelsea are really committed to preparing their squad for 2014-15 and beyond, surely the young Belgian's interests would have been best served in West London.
Having him in the squad would definitely ease the burden on Torres' absence, also.
After missing out on Rooney last summer, it was a wise move to bring in an experienced figure such as Eto'o. What the Cameroonian's arrival outlined, however, was how naive Chelsea had been in targeting Rooney with little to offer in terms of a backup plan.
Three strikers aren't enough to sustain challenges across the board for major silverware, and while Chelsea have gotten away with it thus far, now that we're hitting a vital stage of the campaign, it could prove the time it comes back to haunt them.
Mourinho has made smart moves elsewhere with his squad. Nemanja Matic has been added to address Chelsea's problems in defensive midfield, while Brazilian Willian is beginning to look much more than a signing made to spite London rivals Tottenham Hotspur.
Torres spending a significant period on the treatment table, though, stands to serve how naive Chelsea have been in addressing their shortcomings elsewhere.
Garry Hayes is Bleacher Report's lead Chelsea correspondent and will be following the club from a London base throughout the 2013-14 season. Follow him on Twitter @garryhayes