United has stuck to its "not for sale" stance over the unsettled Rooney following two bids from the London club, but Chelsea manager Jose Mourinho's declaration that he will lodge a third offer for the England international has added further intrigue around the game at Old Trafford.
Rooney, who indicated toward the end of last season that he wanted to leave United, isn't guaranteed to start Monday as he remains short of full match fitness but his body language will be scrutinized if he plays any part in the first major showdown of the new season.
The visitors will be looking to demonstrate to Rooney that they are the new force in English football following the much-heralded return of Mourinho and their perfect start to the campaign, which has seen them record wins over Hull and Aston Villa to go to the top of the early standings.
United also began well, beating Swansea 4-1 away in David Moyes' first competitive match in charge of the Premier League champions.
"In Mourinho's first spell at Chelsea, they obviously got off to a few good starts and we didn't manage to catch them," veteran United midfielder Ryan Giggs said. "It has obviously been well documented that we have got a tough start, but we started well with a good win at Swansea on Saturday and hopefully we can carry that on."
After Chelsea, United plays Liverpool and Manchester City across its next three games so a loss on Monday will pile the pressure on Moyes.
And he'll be given no respite from Mourinho, who isn't giving up in the chase for Rooney in the remaining days of the transfer window. The Portuguese coach insisted Wednesday, though, that a new offer won't be made before Monday's match.
"We did (bid for Rooney) before and we will do later, but I think this period — from the ethical point of view — is a period when we are going to be quiet and just thinking about that game," Mourinho said.
The title race this season is expected to be fought out by United, Chelsea and City, and all three looked in sharp form in the opening days of the season.
City, with its new and improved forward line, appeared to be able to score at will in its 4-0 thrashing of Newcastle on Monday and a visit to promoted Cardiff on Sunday shouldn't pose too many problems.
"One of our main targets for this season is to win the title back," City right back Pablo Zabaleta said. "We know how difficult it is. It is still a long way to go but we are very positive. We have a very strong squad."
Cardiff and fellow promoted clubs Hull and Crystal Palace failed to score a goal between them on the opening weekend, showing how tough the step-up will be from the second-tier League Championship.
While it gets no easier for Cardiff this weekend, Hull will fancy its chances of picking up its first points of the season in a home match against Norwich and Palace travels to Stoke on Saturday after opening up with a 1-0 loss at home to Tottenham.
Also Saturday, it's: Fulham vs. Arsenal; Aston Villa vs. Liverpool; Everton vs. West Bromwich Albion; Newcastle vs. West Ham; and Southampton vs. Sunderland.
Tottenham hosts Swansea in Sunday's other game.