The champions will be without captain Nemanja Vidic for the rest of the season because of a knee injury while striker Javier Hernandez, Anderson and Tom Cleverly are also sidelined.
Midfielder Darren Fletcher's indefinite absence because of illness will also stretch Ferguson's squad thin as they compete at the top of the table with Manchester City but the Scot is unlikely to rush to the post-Christmas sales.
"Not necessarily. I don't know why people keep going on about that," Ferguson told reporters when asked if he would be spending in January.
"We've always viewed it as unless a player we've always been interested in appears - which there is no sign of at the moment - it's not always suitable to us.
"Darren is a great loss of course, being such a great professional, and it's not easy to replace that."
He added that he could not put a timescale on the absence of Fletcher who has a chronic bowel condition but whose illness had initially been described by the club as a virus before the player decided to put the record straight.
"We were talking about a virus, that was down to protecting Darren, but it got to the position... where there was more delving into why we kept talking about a virus and I think Darren was a bit uncomfortable about it so he decided to make it public," Ferguson explained.
On a day when United learned they would be facing fellow former European champions Ajax Amsterdam in a tough tie in the second tier Europa League, there were some positives.
Ferguson said striker Dimitar Berbatov had recovered from a foot injury and should be fit for Sunday's trip to Queens Park Rangers in the Premier League, while defender Rafael was back in training.
If they win at Loftus Road, they would go top of the table at least for a few hours as leaders Manchester City host Arsenal later in the day.
United have 36 points from 15 games, two fewer than their city rivals and five more than third-placed Chelsea and fourth-placed Tottenham Hotspur.
