The 'Special One' famously tried to play down the relevance of that rivalry and one with Porto when joining the Portuguese giants earlier this year.
Mourinho mind games?
"I don't think they (Porto and Sporting) will be upset if I say that after joining Benfica, I spoke with Porto president Andre Villas-Boas and Sporting president Frederico Varandas," he said.
"If we have a good relationship, if we're friends and respect each other, the fact that I'm Benfica coach doesn't mean I've come here to wage war."
That gesture isn't likely to mean anything if Mourinho just so happens to allow the sense of occasion to get the better of him, as he has so often in the past.
Various Barcelona vs Real Madrid and Chelsea vs Arsenal clashes always had an edge to them due in no small part to the Portuguese's mind games.
A draw would favour Porto
Flashscore's Mario Rui Ventura believes that the 62-year-old's presence could even be what swings the game in Benfica's favour.
"The Mourinho factor could be important in this game," he said.
"The Lisbon derby always tends to be decided by small details, and this could be one of them.
"In addition, the fact that Benfica are playing at home and are behind in the standings puts more pressure on the Eagles for this game."
In any event, Mourinho's old club, Porto, sit atop the table at present, winning 11 and drawing one of their 12 games to date.
They're three points ahead of Sporting and six in front of Benfica, and would surely be delighted if Friday's epic encounter ended in a draw.
Benfica haven't beaten Sporting in the league since 2023
Recent history in the fixture favours Sporting, as they haven't lost to As Aguias in the league since November 2023.
However, Benfica are unbeaten in home Primeira Liga matches this season with three wins and three draws from their six contests. In fact, they are still unbeaten in the league, home or away, despite being third.
Quite remarkably, Benfica have not lost a league match at home since April 7th, 2023, against Porto. The last time they lost any league match was back in January, last season, against Casa Pia.
Sporting's league form away from home is almost just as impressive as that, however. Their 16-match unbeaten streak away from Jose Alvalade Stadium stretches back to December 2024 against Moreirense, and they've won every away game they've played this season.
Suarez, Goncalves and Pavlidis likely to decide the outcome
Sporting have also scored the most goals in the division with 31, due in no small part to the efforts of Luis Suarez and Pedro Goncalves ('Pote'), who have scored nine and eight times, respectively.
Suarez has taken the most shots for his team this season (55) and had the most on target (25), whilst Pote has provided the most assists (five) and created the most chances (32).
10 of Benfica's 25 goals have been scored by Vangelis Pavlidis, making him the top scorer in the league. Three of those have also been opening goals, setting the tone for the matches to follow.
Pavlidis' three assists are the joint most for the Eagles with Dodi Lukebakio, whilst his 39 shots (and 20 on target) are the best return in the Benfica squad.
After not scoring against Sporting on four occasions last season, the Greek marksman hit the game-winner against them in the Portuguese Super Cup, and his form since should at least make Mourinho think twice about entering the transfer market for another striker in January.
Benfica's performance levels must be improved
The Eagles do need to build on their all-round performance levels, however.
"One of Benfica's major problems this season has been a lack of consistency," Flashscore's Mario Rui Ventura added.
"The truth is that the victory against Ajax, their first in the Champions League, may have given Jose Mourinho's squad a morale boost.
"On the other hand, however, Sporting is enjoying one of its best moments of the season, and a victory against their rivals Benfica, after losing the classic against FC Porto, could say a lot about the rest of the season."
Both teams are evenly matched in several areas, though.
Sporting's 31 goals scored, 245 total shots taken, and 91 shots on target, as well as a collective passing accuracy of 87%, are all best-in-class.
Benfica are placed second for goals scored (25), total shots taken (202) and shots on target (74), and third for collective passing accuracy (86%).
As Mario Rui Ventura notes: "It will be another derby full of excitement, with a totally unpredictable result and no clear favourite. Although Sporting are higher in the standings and have been performing better, Benfica are playing at home, have been improving, and will always have the Estadio da Luz and Jose Mourinho on their side."
