Not for the first time, United find their backs pressed up against a wall approaching a big European night.
Porto’s last-gasp equaliser at Old Trafford in the first leg earned a draw which makes them favourites to advance at the Estadio do Dragao.
With two away goals to claw back, it seems unlikely United can get through with anything other than an away win, something no English side has managed in Porto before.
But the omens were just as bad in Turin a decade ago, and United promptly fell two goals behind before a Roy Keane-inspired comeback saw them beat Juventus on their way to ultimate glory against Bayern Munich at the Nou Camp.
There have been other memorable triumphs since then, in Rome last season, and a brilliant performance that earned only a draw with Inter Milan at the San Siro two months ago.
However, that Juventus game stands as the beacon United hope will light the path to Rome on May 27.
“We have had a lot of good European nights but Juventus is probably the one that stands out,” reflected Ferguson.
“After a draw at home, we won away, which we hope is the same again. It was a night when a lot of the big players played well.
“There are plenty of performances we would like to replicate and I trust these players to do it.
“They deserve that because of their performances over the last two or three years in big away games in Europe.”
The major plus for Ferguson is the availability of Rio Ferdinand.
Although the England defender has only been missing for three games with a groin injury, his absence is one of the reasons United have found it so hard to keep clean sheets of late.
It is five games now since they last held the opposition at bay, including last Tuesday when the Porto strikers led their hosts a merry dance before eventually fading.
Ferguson does believe Saturday’s nervy win at Sunderland will prove to be a watershed, with Ferdinand a major defensive weapon.
“There is a lot of quality in Rio’s game, so he is obviously going to make a difference,” said Ferguson.
“Also it gets us back the partnership between Rio and Nemanja Vidic, which has been the cornerstone of our great defensive performances this season.”
It seems certain Ryan Giggs rather than fellow veteran Paul Scholes will be asked to take up a central midfield station, with Park Ji-Sung supplying added tenacity in the United engine room now that Darren Fletcher has been ruled out with a hamstring injury.
That means Wayne Rooney and Cristiano Ronaldo will provide attacking support to Dimitar Berbatov. Ferguson was surprisingly critical of Ronaldo at the weekend, when he suggested the Portugal superstar sometimes forgets his responsibilities to team-mates when he is raging at injustices.
The Scot was not reopening debate. But he does not appear to be backing down either.
“Attacking players are all the same, they prefer to be attacking,” said Ferguson. “They want to be on the ball all the time. But part of the job is to be part of the team. When you lose possession you have to think about the team.”
Ferguson did deflect attention away from Ronaldo when he responded to the suggestion his most talked-about player needed to produce a performance that mattered, claiming he needed every United star to reach their peak.
“Cristiano is part of our team,” said Ferguson. “They all have to be up for it. There is no point choosing one individual. They have all got to step up to the plate.”
Ferguson will be the only manager in the dug-out tonight after opposite number Jesualdo Ferreira was banned for one match by UEFA following a tirade at an official that accompanied a disallowed goal against Atletico Madrid in the previous round.
The news came as a surprise to Ferguson, although it did provide him with the opportunity to have a little dig at Rafael Benitez, who has been prodding the United boss with increasing regularity over the last few weeks.
“Why was he banned? I knew he hadn’t attacked me — unlike someone else I know,” smiled Ferguson.