United have failed with two bids to sign former Arsenal midfielder Cesc Fabregas from Barcelona and also lost out on Thiago Alcantara, who chose to join European champions Bayern Munich.
That leaves full-back Guillermo Varela - signed from Atletico Penarol - as the sole arrival of the David Moyes era, although January signing Wilfried Zaha is now at Old Trafford having returned to Crystal Palace on loan last season.
But Ferdinand is bullish about the champions' prospects for the new campaign regardless of what happens between now and the transfer window closing.
He said: "We're confident. If we had to go into the season with the players that we've got now I'd be more than confident and with high hopes of doing well and winning trophies.
"If the manager adds to that and chooses to add to that, then great - but it remains to be seen."
Moyes himself appears similarly enthused by the options at his disposal.
He reflected on the tour of Asia: "I'm taking away a great experience of my first trip with Manchester United in general and what the football club means around the world.
"But I've also had a chance to get to know the players, try and settle into my new environment and the players to get to know me as well.
"They've been working with a great manager for a long time, a lot of them, so it's going to take time. But I've enjoyed working with them, they're incredibly professional and I can see why they're champions. The way they conduct themselves and go about their business and I've been very impressed by them."