The reigning English champions are currently second in the Premier League table and in touch with leaders and cross-town rivals Manchester City.
But a squad already without the likes of the injured Nemanja Vidic, Javier Hernandez, Michael Owen, Tom Cleverley, Anderson, Rafael and Fabio face five matches in 18 days starting with Sunday's match away to QPR.
The Premier League has been given additional importance at Old Trafford this term following the club's shock first round exit in the Champions League and Ferguson has long believed the team's position at the turn of the year will be a good indication of their domestic title hopes.
"December is a particularly busy month when we often play eight or nine games," he told Inside United.
"We've got a Boxing Day Game, a New Year's Eve game… it's going to be a hectic spell and that's when the squad really kicks in."
Ferguson has rarely had any great faith in the quality of signings to be had in the January transfer window and last week played down suggestions of bringing new players to Old Trafford midway through the season.
However, former United midfielder Nicky Butt urged Ferguson to seize any opportunity to strengthen his squad.
"Every team can improve, no matter who they are," Butt told manutd.com.
"Even Barcelona can improve so I'm sure Sir Alex will sign players, whether it be in midfield, defence or up front.
"He's always looking to enhance his squad."
Butt added: "I think it's difficult to pick the four starting across the midfield. In years gone by, everyone knew who the strongest four or five was. It's different now but we've still got some good players.
"I think Sir Alex will be looking to try and get a steady pairing in the centre.
"He's had injuries to Darren Fletcher, Cleverley and Anderson so it's been difficult to get a regular line-up in midfield. It helps when you can get everyone on a roll and playing well together."
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