PSG, without injured spearhead Zlatan Ibrahimovic, do not actually need to score any goals at Stamford Bridge to knock Chelsea out following their 3-1 first leg win in Paris.
It probably will not be as simple as that though, as Chelsea know a 2-0 win will see them through on the away goals rule.
Even if his strikers again fail to impress Mourinho, Chelsea have an array of midfielders capable of swinging the tie in favour of the London club.
PSG do, though, start the match with a healthy advantage after Javier Pastore’s goal with the last kick of the game at the Parc des Princes last week gave them a buffer.
However, Chelsea at Stamford Bridge are a different proposition to the team that have lost their last three away matches in all competitions.
On Saturday they brushed Stoke City aside 3-0 in the Premier League, with all three goals coming from midfielders: Mohamed Salah, Willian and Frank Lampard, who has now scored 250 club goals for West Ham United, Swansea City and Chelsea.
He also has another 29 for England.
Saturday’s match was also their eighth successive home game with conceding a goal, and kept them two points behind Liverpool in the Premier League title race.
It was their 77th unbeaten home league match in Mourinho’s two spells at the club, and they have also proved in the past in Europe, most recently against Napoli two seasons ago, that no task is to large for them to overcome at Stamford Bridge.
Mourinho was not in charge of Chelsea when they overturned a 3-1 first leg defeat by Napoli in the round of 16 in 2012, winning 4-1 at home in the return match before going on to win the trophy in Munich.
While he has never lost a quarter-final tie with Porto, Chelsea, Inter Milan or Real Madrid, he has also never overturned a two-goal first leg deficit in European competition.
“We know it won’t be easy at home but we can turn the tie around,” midfielder Eden Hazard, who scored from the penalty spot and hit the woodwork in the first leg, said.
“We have proved we can do this before, and we can do it again next week.”
Winger Andre Schurrle, preferred to 50-million-pound striker Fernando Torres in Paris, agreed they were down after the defeat, but not out.
“It’s the worst time of the season to get results like this (but) we are a different team at Stamford Bridge with our fans behind us. It will be difficult but it is not impossible.”
There is some comfort in the absence of Ibrahimovic, who has scored 25 league goals this season in 30 appearances and played under Mourinho in Italy.
He is missing after hurting his hamstring in the first leg.
PSG, who beat Reims 3-0 on Saturday without Ibrahimovic, are 13 points clear of Monaco at the top of Ligue 1 and are confident they can overcome Chelsea without their talisman.
Ezequiel Lavezzi put on a man-of-the-match display at the Parc des Princes against Chelsea and Edinson Cavani scored the opener against Reims.
Both players were in the Napoli team that went out to Chelsea 5-4 on aggregate in 2012.
With Ibrahimovic sidelined, coach Laurent Blanc will field Cavani as number nine with Lavezzi and Lucas on the left and right flanks respectively.
Blanc insisted PSG will stay true to their style even without Ibrahimovic.
“Our philosophy and our tactics will not change,” he said.
The only uncertainty is regarding who will start as right back, although Gregory van der Wiel appeared comfortable after returning from a knee injury against Reims, providing the cross for Cavani’s opener.
(Additional reporting by Julien Pretot; Editing by Josh Reich)