A 12,000-mile round trip in the hope of being crowned the world's best could take its toll on United's players as they bid to defend their English and European titles.
Part-timers Waitakere United should be safely back home in New Zealand's summer sunshine by the time the "Red Devils" sweep through customs into Tokyo's wintry chill early next Monday.
Two more of the seven teams will also have packed and left before Cristiano Ronaldo has removed his eye-mask and stepped off the long flight from London.
However, FIFA president Sepp Blatter will be hoping the December 11-21 tournament delivers more quality than the last few editions before United join the fray at the semi-final stage.
Dismal early games before the champions of Europe and South America get down to business has done little to boost the competition's credibility, a fact conceded by Blatter.
Swathes of empty seats have not helped FIFA's case and Thursday's curtain raiser between Waitakere and Adelaide United in Tokyo hardly sets pulses racing.
AC Milan broke Europe's Club World Cup jinx by beating Argentina's Boca Juniors 4-2 in last year's final after Barcelona and Liverpool had failed in 2005 and 2006.
FIFA staged a first world club championship in 2000 when Brazil's Corinthians won, but pulled the plug on the competition in 2001 after the collapse of marketing partner ISMM/ISL.
The revamped competition moves to the United Arab Emirates next year.
'GREAT ACHIEVEMENT'
United beat Brazil's Palmeiras 1-0 in 1999 in the tournament's forerunner, a one-off game between the champions of Europe and South America.
"We're the only British team to have won it," said United manager Alex Ferguson, whose side face Tottenham Hotspur in the Premier League at the weekend before jetting to the Far East.
"I consider that to be one of the club's greatest achievements."
Ecuador's LDU are likely to be United's biggest threat after becoming the first team from their country to win South America's Libertadores Cup.
The Quito-based side face the winners of the first quarter-final between Mexico's Pachuca and Al Ahly of Egypt.
Ferguson's team, currently trailing Premiership leaders Liverpool by six points with one game in hand, play in the second semi-final on December 18.
Barring an upset, United will play Japan's Gamba Osaka, themselves expected to meet Adelaide in a replay of last month's Asian Champions League final, which Gamba won 5-0 on aggregate.
While a semi-final exit for Ferguson's men is almost unthinkable, it would be a surprise if LDU failed to keep their end of the bargain by reaching the championship match in Yokohama.
Ferguson would then pit his wits against LDU's Argentine coach Edgardo Bauza, who goes by the nickname "Big Duck" -- a first, even for the United manager.
