Already a game behind after their appearance at the European Super Cup, United will add a postponed game against Wigan on December 21 to their backlog due to their commitments at the World Club Cup in Japan.
"We will be away for 10 days and coming back will be a test for us," said Ferguson. "That is where the league will be decided. How we handle that period will be crucial."
Ahead of Saturday's trip to Everton, Ferguson notes with a wry smile that his side will have faced last season's top eight away from home before they leave for the Far East.
"They say the league is not handicapped," he said.
Not that Ferguson would have it any other way. If fate had not intervened, John Terry might have stayed on his feet as he strode up to take that fateful penalty for Chelsea in the Luzhniki Stadium and the Londoners would have scored, leaving them to juggle the fixture difficulties.
Unsurprisingly, Ferguson prefers it just the way it is.
"Of course it is worth it," he said. "It is the world championship and we are the only English team to have won it. We are only in it because we have won the European Cup, so I hope we are in it for the next three years."
Nevertheless, United need to continue their six-match winning streak on Saturday as Ferguson feels matches in hand during 2009 may not necessarily translate into victories.
"By the time we get to the end of December we will have two games to make up," he said. "If we were to have a good run in the League Cup - United face QPR at Old Trafford in the fourth round next month - which we have to try and do to be successful at all levels, the second-half of the season is going to be a big test for us.
"By New Year's Day we need to be around the top of the league to give ourselves a proper chance because those two games may be difficult for us."