While Inter boss Jose Mourinho predicts the clash will go to extra-time at Old Trafford in a fortnight, Ferguson is looking at a far more rapid conclusion.
And that means an injury-hit United side grabbing a priceless away goal.
"I don't think it will go to extra-time - it will be decided tonight," said Ferguson.
"If we score we will have a great chance."
Not that Ferguson is dismissing Inter. Mourinho has only lost one of 12 head-to-head duels with the Scot, so that would be a foolhardy move.
"At this moment in time you cannot split the teams," he said.
"Inter have won Serie A three times in a row and are going to win it for a fourth time. They have experience; they have a really outstanding manager and some terrific footballers.
"It is a really big game. It would have been a great final."
Among the visitors to see United go through their paces at the San Siro ahead of the game was David Beckham, currently on loan at AC Milan.
HeadachesBeckham spent a happy hour with the Red Devils when he was reunited with Ferguson.
He then headed to United's team hotel, where he met former team-mates Paul Scholes and Ryan Giggs.
United go into the game with defensive headaches with Nemanja Vidic suspended, while Jonny Evans, Wes Brown, Gary Neville and Rafael da Silva are injured. John O'Shea is also struggling.
Ferguson's problem is compounded by his opinion that Zlatan Ibrahimovic is Inter's best player, if not quite the world's best as Mourinho boldly claimed a couple of months ago.
The Swede has often failed to do himself justice on the biggest stage. But this season has been Ibrahimovic's best so far, which was threatening to cause the Red Devils a problem even before their defence was ripped apart.
"Without question, Ibrahimovic is their star player," said Ferguson.
"I have watched him for many years now. He has developed and is at an age now where you expect a bit of maturity. He is getting all the praise he deserves."