United have been recently linked with Everton left-back Leighton Baines and Portugal midfielder Joao Moutinho, and Ferguson said they were working on adding to their squad.
"Yes, there's a possibility. We’re working on one or two things but there’s nothing really to tell you to be honest," he said.
Japanese star Shinji Kagawa has been United's biggest summer signing to date, arriving from Borussia Dortmund, while Nick Powell was bought from Crewe.
"We always try to get our work done at the end of the season – we spent a good deal of time sorting the deal with Shinji and we’d agreed a deal with Nick Powell before the play-offs which was a good move by us because the boy had an outstanding final at Wembley," Ferguson said.
"When you don’t get deals done immediately and you’re negotiating with a club over a long period, then you can’t expect to just snap your fingers and get it done."