Sky Sports News presenter and in-the-know transfer man Jim White revealed on Saturday that the Red Devils had jumped in for the centre-back, perhaps not so coincidentally after their 2-1 loss at home to Swansea City:
As Metro attest, the club's first opening-day home defeat since 1972 exposed United's lack of defensive pedigree, which could see the Blues miss out as Louis van Gaal seeks to shore up his back line.
However, it may be a blessing in disguise for Jose Mourinho, who already possesses a vast wealth of talent in that area and would be forced to make use of it should Benatia head elsewhere.
Chelsea begin their Premier League season with a trip to Burnley on Monday evening, and evidence would suggest that John Terry and Gary Cahill are likely to start at centre-back.
That leaves Branislav Ivanovic providing cover at central defence, alongside youngsters Andreas Christensen, Nathan Ake and Kurt Zouma, although Ian Holyman of ESPN FC reports the latter could leave the club on loan:
Chelsea are currently operating on a sell-to-buy basis so that they may comply with the Premier League's quota, prescribing that any club has a maximum of 17 overseas players over the age of 21 in their squad.
Given that Zouma is only 19 years old, his departure wouldn't yield any great benefit for Mourinho in terms of adding more players to his roster, however, and so it would make more sense to keep the former Saint-Etienne star around.
Youth promotion isn't an aspect of football Chelsea are renowned for, opting to loan their products out so that more senior stars can reign in the first team, but their resources in young assets are brimming with talent.
The West Londoners face another obstacle in signing Benatia, with Norwegian pundit Jan Aage Fjortoft suggesting that Bayern Munich are in the hunt for the Moroccan as a replacement for the injured Javi Martinez:
Terry's days at Stamford Bridge are admittedly nearing an end. With less than a year once again left on his newly extended one-year deal, it's understandable that a replacement should be sought.
However, the 33-year-old Terry continues to defy his age and remains a figure deserving of his place in the starting XI. Alongside Cahill, Terry formed part of the Premier League's best defence last season, a unit that conceded 10 fewer goals (27) than champions Manchester City.
The idea of an unnecessary luxury is of course nothing new to the Blues, the club having splurged in the past so that they might amass a long line of options across the squad.
However, Financial Fair Play is changing the transfer scene, and so these luxuries must be minimised, Benatia representing one deal the club might want but are not desperate for.