Two days after Torres' late goal gave Chelsea victory over Manchester City in the Premier League, a Blues side showing 10 changes claimed a 2-0 win at Arsenal to advance in the League Cup with a sixth win from six games in October.
Now out of that competition following the midweek loss at Sunderland, Chelsea's immediate focus is on the championship and claiming a third successive win at Arsenal following last season's Premier League triumph.
Torres, who netted in the September 2012 win, said on chelseafc.com: "We know how important it is for us. It's a chance to overtake them in the table and we know how important that is for the fans.
"We're playing Arsenal, and it's a huge game for both sets of fans.
"We've beaten them once this season in the Capital One Cup at the Emirates, so we know what we need to do to win there.
"We just have to ensure we prepare for the game the best we can, and I'm sure we can go and do it."
A win in the first of four games in 10 days would take Chelsea above the Gunners and level in first place with a Liverpool side which visits Stamford Bridge on December 29.
Mata was on target in last season's Premier League win over Arsenal and in the Capital One Cup earlier this season, when he was out of favour.
The Spaniard, who is still to claim a regular starting place, told Chelsea TV: "They are playing really well at the Emirates, but we won there in the Capital One Cup this season.
"We'll try to play great football like we did that game and we'll try to get the three points to get to the top of the table.
"It's a team I enjoy playing against. They are a team that play with the ball and in a way they let you play with the ball as well.
"I've been lucky against them. I scored at Stamford Bridge twice in two games, I scored at the Emirates twice."
There will be familiar opposition facing Torres and Mata, if the pair are selected, with Spaniards Santi Cazorla, Nacho Monreal and Mikel Arteta in the Gunners squad.
"They are my friends," Mata added.
"Santi is an amazing player, he can play with both feet. Nacho is a very consistent left-back and Mikel is one of the most important players in the team because he's the centre of their football.
"In the midfield they have a lot of players that can play with quality. We will have to be careful with them."
Mourinho has an unbeaten record against Arsene Wenger's Arsenal.
In eight meetings of Mourinho's first spell, the Portuguese won four times and drew four, while the Capital One Cup success enhanced his record.
The self-proclaimed Special One insisted the record was not relevant heading into the contest in which England left-back Ashley Cole is to be left "on the bench or at home".
The defender, who joined Chelsea from Arsenal in controversial circumstances in August 2006, attended his former club's Christmas party last week and was already out of favour, having not played a Premier League game since November 2 at Newcastle.
Cesar Azpilicueta is preferred, with Branislav Ivanovic back following suspension.
Captain John Terry is to be joined in central defence by Gary Cahill or David Luiz.
What will be intriguing is how Mourinho's attacking selection and set up.
He has repeatedly bemoaned his strikers' failings in front of goal - Torres, Samuel Eto'o and Demba Ba have five Premier League goals between them all season, none away from home - and insisted his attacking players must do more defensively if their impotent performances in front of goal do not improve.
Mourinho insists he will not change his approach, but he may opt for an extra player in central midfield to combat an Arsenal strength and change from a 4-2-3-1 formation to 4-3-3.