The opponents are apt. In a season that could encompass 70 games, Chelsea are stretching the boundaries of footballing possibilities.
In Europe, they come up against a team near the borders of the continent, Rubin Kazan, whose home is some 450 miles east of Moscow and, thus, almost in Asia. It is so far, indeed, that it is so cold that next week's second leg has to be played in comparatively balmy Moscow.
First, however, Chelsea welcome Kazan to Stamford Bridge for their Europa League quarter-final first le - their third game in six days.
"We proved against a team at the top of the table and a manager with the most trophies in England that we can compete against anyone if we have the time and players available."
But exhaustion creates opportunities and a tiring run ensures another chance for the old guard.
There was a time when it would have been impossible to conceive of Chelsea facing United and choosing not to deploy John Terry or Frank Lampard.
Not now. Both captain and vice-captain were unused substitutes three days ago.
Circumstances mean both are set to start on Thursday night.
"We concentrate one game at a time so we pick a team who can win any game and concentrate on this game," said Benitez, the great advocate of squad rotation.
"They have to be ready for any game."
His reservations about Terry's match fitness since his recovery from a knee injury are well known; they may be emphasised to conceal his concerns about the Englishman's lack of pace.
Terry is rarely selected against the speedier strikers in the Premier League but, after starting the past three European games, he is invariably parachuted in for continental competition.
With Benitez ruling out both Ashley Cole and Gary Cahill for two weeks, Terry is almost guaranteed a game Thursday night.
So, too, is his close ally.
Over a dozen years, Lampard has been the great constant on the Chelsea team sheet and, as often as not, the score sheet.
With 12 goals in his past 23 games under Benitez, he has maintained his prolific return.
Yet his omission against United, along with his substitution in their first game at Old Trafford, was a sign Benitez prefers a specialist anchorman, in John Obi Mikel, against elite opposition.
Versus the rest, however, Lampard can continue his pursuit of Bobby Tambling's club record of 202 goals. He is only two behind the scorer from the 1960s.
Because Chelsea's two stalwarts are in their twilight years and because of the complications of managing the squad in such a crowded fixture list, the Europa League brings reunions of the rich and famous.
There is scarcely surprise when Fernando Torres is omitted anymore and the alternative, Demba Ba, scored a wonderful winner to sink United. But the Senegalese is ineligible in Europe after appearing in the group stages for Newcastle United earlier this season.
Torres is an automatic choice again, albeit not in the circumstances he would prefer.
Without a league goal in 2013, the Spaniard's only significant strike so far this year came in the last round against Steaua Bucharest, even if he rather marred that good work by then missing a penalty.
But after being a bit-part player when Chelsea won the Uefa Champions League last season, he has the chance to play a pivotal role in their quest to triumph in a competition they never intended to enter.
And Chelsea, the club whose sights were set on world domination, now have the opportunity to create a rare piece of history: having won the Uefa Champions League and the defunct Cup Winners' Cup, they can join the select group to win all three European trophies.
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