"There are no favourites in these type of games," said Benfica coach Jorge Jesus in his pre-match press conference. A stock line, perhaps, but a pertinent one to describe the relevant factors to consider in a confrontation of such magnified importance, when there is such a gulf between the duopoly of Jesus' side and current Liga champions Porto, compared to the rest.
Such inequality should come as no surprise in a nation where only five clubs have ever won the league in 77 years of competition (and two of those have won it just once), but Porto against Benfica is always a match apart, with such "cultural and emotional rivalry", as Porto coach Vitor Pereira describes it, and much more than the constituent sporting elements will decide proceedings.
The clássico has come so soon that there's a sense of stepping into the unknown, with players giving cagey, wan quotes and the Portuguese press filling the vacuum by trotting out reams of historical head-to-head statistics. We'll only really know what's what on Friday night, as it's not just a question of quality, but of whether the Lisbon giants have recovered from the significant psychological blows rained down upon them by their northern rivals last season. Porto won three out of the four meetings between the pair last term, each time ramping up the level of humiliation for their opponents. After taking a 5-0 beating at the Dragao in the pair's first league meeting of 2010-11, in November last year, Benfica came back to record a superb 2-0 win there in the Taça de Portugal semi-final first leg at the start of February, but far worse was yet to come.
At the start of April, Porto won at the Estadio da Luz to take the league title from Benfica on their own patch. The hosts tried to block out this horror by turning out the lights and pumping Benfica anthems over the public address system, but there was no hiding place 17 days later, when Andre Villas-Boas and company returned for the delayed semi-final second leg - and won 3-1 to dump Benfica out on away goals. The Eagles were exasperated; having ruled the roost with considerable élan in 2009-10, they were incontrovertibly second best.
A huge part of that swing was Hulk, a man with a point to prove against Benfica after the costly personal consequences of his central role in the Luz tunnel brawl of December 2009. Jesus has this week tried to play down the bogeyman aura of Porto's key forward. "He's got special qualities that we know about, but we're not going to do anything extra for him," said Jesus. "We don't have an individual strategy for any Porto player," he continued, not necessarily reverting to cliché but perhaps mindful of the decision to move David Luiz to left-back to face his countryman at the Dragao last November - a strategy that spectacularly backfired in a heavy defeat, as Hulk ran riot.
Parallels between this match and the Porto procession in the corresponding fixture should not be overdone, however. Last season's game marked the point of the campaign already being one-third done and, by that stage, Porto's advantage was not merely in terms of morale - the win saw them open a ten-point gap over Benfica. The two sides go into this one locked together on 13 points each, so there is little question of a decisive blow being struck.
That said, the ball is very much in Benfica's court to demonstrate a level of recovery from last season's stumbling finish, after which they ended 21 points behind Porto. Jesus himself is under the microscope, despite his (quite correct) point that after three trophies in two seasons, he is the most successful Benfica coach for some years. On arrival, the 57-year-old had sparked the Luz into life with his flamboyant approach, manifested in a team of quite spectacular verve, which scored over 100 goals in all competitions in his debut campaign.
Though the latter achievement was repeated in his sophomore season, critics suggested that Jesus' confidence was a glitzy sheen, easily scratched away by failure. A poor start to the last campaign left the coach on the back foot, and making defensive substitutions to close out much-needed wins; a sensible policy that, by defying a caricature, gave the naysayers ammunition.
Any supposition that this season's experiments in morphing from his typical 4-4-2 to a 4-2-3-1 (as in, for example, the Champions League clash with Manchester United) show a reticence prompted by bitter experience would be misguided. Such is the versatility and creativity offered in midfield not only by the outstanding Axel Witsel and free-scoring wide man Nolito, as well as Bruno Cesar and the currently injured Enzo Perez, that Jesus is simply creating more space for the talent to breathe, leaving just Oscar Cardozo up top.
Villas-Boas' successor - and erstwhile assistant - Pereira has a similar plethora of options at his disposal. Despite the sale of Europa League record scorer Radamel Falcao to Atletico Madrid, the Liga and Europa League holders arguably have a stronger group than last term, following the retention of most of their key elements and a record €43m aggregate spend to reinforce for the future, including the addition of their own Belgian midfield maestro in Steven Defour. Falcao's replacement Kléber has just been called up to the Brazil squad together with new club-mate Hulk, though rising star James Rodriguez will be suspended following last week's foolish red card against Feirense.
Peireira has much to prove himself in his first major domestic test as the boss, but he has already absorbed the necessary lessons in top-level lexicon. "What motivates us is real competition," he told journalists on Thursday. "At this level, we're competitive animals and it's natural that this type of game is the boost for us to reach our maximum potential."
The season's first clássico promises to be an early test of mental strength, if maybe not a definitive decree of which team has the tools to last the distance. What it most certainly should prove is that Portuguese football's two perpetual giants are in rude health as they aim to challenge on all fronts, at home and abroad.