The United manager expects his key midfield player Roy Keane to shake off the ankle injury that forced him to miss Saturday's 3-1 home win over Coventry, and that means only the long-term casualties, Paul Scholes and Nicky Butt, will be ruled out of the club's biggest night for 28 years.
Ferguson knows that he must find the right blend to see off the Portuguese standard-bearers if the Premiership leaders are to take the right result into the return in Portugal two weeks later.
Ole Gunnar Solskjaer, their top scorer with 13 goals, was rested against Coventry on a day when David May made his first start for seven weeks after an operation on a hernia problem, while Eric Cantona returned after a two-match suspension.
Karel Poborsky marked a rare starting appearance with a goal, while Jordi Cruyff also came in to produce an effective midfield display that further strengthens Ferguson's hand.
Brian McClair, Ronny Johnsen and Phil Neville, the latter making his first appearance since 21 December after a bout of glandular fever, were all given second-half run-outs from the substitutes' bench.
Keane, the talismanic Irishman who is the heartbeat of United's midfield, will definitely return if he proves his fitness and Ferguson believes he will. "Roy should make it," Ferguson said. "I'm hoping that he will be OK and I think he will.
"He is a very important player for us and although he couldn't play against Coventry, he should be there against Porto."
However, Solskjaer faces an anxious wait to see if his manager opts for a one or two-man strikeforce, with the rejuvenated Andy Cole at last beginning to show the form that prompted United to splash out pounds 7m for his services just over two years ago.
"Ole was rested with Wednesday's game in mind because we feel he does better when he's fresh," Ferguson said.
"He's still got to get that first full season under his belt and then get a pre-season and he'll be much better for that. That's why I have to think about what's best for him and make sure that I don't over-use him. He's not had a break from football for about two years and hasn't yet had a full pre-season with us."
He added: "With players like Karel Poborsky and Jordi Cruyff also having an impact now, they will give us a real strength in numbers for the important part of the run-in."
It is all looking good for Ferguson, who is desperate to emulate the Old Trafford legend Sir Matt Busby by landing the Champions' Cup. United's last sniff of ultimate continental glory came in 1969 when, as the defending European champions, they were knocked out at the semi-final stage by Real Madrid.
They have limped rather than surged through the Champions' League stages, but, as Ferguson observed: "The good thing from our point of view is that our players seem to get better at this time of the year and have shown over the past few seasons that they come good during March and April.
"It will be a big test against Porto, make no mistake about that, but the players should be looking forward to the challenge.
"They have got to be really positive about it and try to enjoy it. It will be a big night, but I think they are capable of doing really well."Reuse content