No player has directly moved between Liverpool and Manchester United since Phil Chisnal all the way back in 1964, while just two players have represented both Northwest rivals during the Premier League era - Paul Ince and Michael Owen.
Indeed, any potential transfer between the Premier League giants is pretty much a non-starter and that's probably truer now than ever before with both clubs embroiled in a title race.
But in terms of possible signings from elsewhere, Liverpool and Manchester United have a far more shared history. In fact, more often than not the two rivals are operating in the same bracket of the transfer market, looking at the same calibre of player.
Accordingly, there are a whole host of names closely associated with either Liverpool or Manchester United who at one time or another almost joined the ranks of the other club instead.
So ahead of Sunday's big derby, GIVEMESPORT have taken a look at five Red Devils who almost ended up at Anfield, and five Reds who nearly made the switch to Old Trafford.
Just a year after moving for a monstrous fee, Monaco and Radamel Falcao both appeared to be having doubts about their big-money arrangement.
However Manchester United snapped up the South American assassin instead in a deal that saw him pocket £265k per-week during his time at Old Trafford.
But the striker that scored 142 goals in just 178 appearances for Porto and Atletico clearly wasn't over the very serious ACL injury that had ruled him out for six months, scoring only four times for the Red Devils.
United elected not to make his loan move permanent.
Gabriel Heinze has come as close as any other player to directly moving between the Northwest giants since the aforementioned Chisnal.
Having been bumped down the pecking order by the arrival of Patrice Evra, Heinze was on the scrapheap in summer 2007. Liverpool made a bid for him and Heinze was keen to move to Anfield - but Manchester United outright rejected the offer on the grounds of the Reds being a key divisional rival.
Fair enough it would seem, but Heinze was far from happy and a legislative dispute soon emerged as all parties lawyered up. Eventually, however, a Premier League panel ruled that United had made it clear from the start that they wouldn't let the Argentine join a direct rival.
In the end, the hot-headed defender signed for Real Madrid instead.
Believe it or not, there was once a time in English football when every major club wanted to get their hands on Phil Jones.
Having made his debut for Blackburn as a teenager and quickly established himself in their senior starting XI playing in both defence and midfield, Jones was a promising youngster with numerous plus points.
Sir Alex Ferguson eventually brought him to Old Trafford, but Jones has since revealed he could've instead joined numerous other Premier League clubs, including Manchester City, Arsenal and Liverpool.
Having made more than 20 Premier League starts just once in the last six seasons, however, Jones has ultimately failed to reach his full potential with United.
Perhaps the biggest challenge David Moyes faced upon inheriting a title-winning team from Ferguson was finding a way of replacing Paul Scholes' playmaking influence in midfield.
ButFerguson had already lined up the ideal successor - Barcelona's 22-year-old Thiago Alcantara in a swoop worth just £17m. The deal just needed Moyes' seal of approval to go through.
However, United's 'Chosen One' surprisingly wasn't keen and decided he didn't know enough about the player. Apparently, a perplexed Thiago even asked his agent to check with United for a second time just before he agreed a contract with Bayern Munich, only to be left disappointed again.
At Bayern, the Spaniard would win seven Bundesliga titles and the Champions League before joining Liverpool. United, meanwhile, ended up signing Marouane Fellaini that summer.
Back when anyone loosely associated with Liverpool branded Raheem Sterling a traitor of Benedict Arnold proportions for not signing a new contract with the club that had given him the platform to become a superstar, it was quickly forgotten that the Reds had actually signed him from QPR in 2010 and he was by no means an academy product in the true sense of the phrase.
In fact, Sterling even grew up a United fan and academy director Brian McClair went to watch the England forward in action during an U18 game while still in west London - but ultimately Liverpool beat the Red Devils to the punch.
That wasn't the end of it, however - back in 2012, Ferguson had Sterling in his crosshairs while ambiguity remained over his first major Liverpool contract, apparently identifying him as Nani's successor on the wing.
But nothing materialised and Sterling would end up winning Premier League titles with United's local rivals, Manchester City, instead.
Liverpool's captain and midfield dynamo was recommended to Manchester United by their former skipper Steve Bruce during his time in charge of Sunderland.
However, United weren't quite as convinced as the Black Cats boss and Ferguson later revealed that they'd been put off by Henderson's running style.
He explained: "We noticed he runs from his knees with a straight back. The modern footballer runs from his hips and we thought this gait might cause him problems later in his career."
Ultimately, Ferguson's doubts have proved misguided with Henderson captaining Liverpool to the Champions League and Premier League titles.
Despite being something of an unknown entity when Manchester United first signed him from Spartak Moscow in 2006, it appears Liverpool were well aware of Nemanja Vidic's huge potential.
The Serbian international has revealed since hanging up his boots that Rafa Benitez wanted to bring him to Anfield, however at the time he was concerned about his poor grasp of the English language.
Ferguson, meanwhile, later made a very direct approach and sealed the deal for Vidic within a couple of days.
He'd go on to form an iconic centre-back partnership with Rio Ferdinand, and captain United to their two most recent Premier League titles.
It seems a strange thing to say now, but reports detailing Louis van Gaal's 2015 interest in Southampton forward Sadio Mane were largely met with bemusement from Manchester United fans and even a little ridicule from rival supporters.
Saints boss Ronald Koeman was quick to insist the Senegalese forward wouldn't be sold and rather than moving to Old Trafford, Mane would instead go on to blossom at St. Mary's.
Liverpool came calling a year later and Mane proved an instant hit at Anfield, playing a hand in 18 Premier League goals during his first season there.
He's now well-established as one of Liverpool's most important players in Jurgen Klopp's system and has been crucial to their domestic and European successes over the last few years.
Virgil van Dijk
Jose Mourinho wanted to bring a new centre-back to Old Trafford in summer 2017 and reportedly had three names on his shortlist - Michael Keane, Victor Lindelof and Virgil van Dijk.
Eventually, it was the Swede who completed the move to United, a club where he's made 136 appearances despite never quite convincing as a truly elite centre-half. While working as pundit, Mourinho even criticised Lindelof's aerial ability.
Six months on from being shortlisted by Mourinho, van Dijk moved to Anfield in a deal that is often credited as transforming Liverpool from being great entertainers into legitimate trophy chasers, with the Dutchman providing the much-needed backbone to compliment their attacking talent.
Indeed, van Dijk has helped Liverpool to Champions League and Premier League titles and his absence through injury this season has been sorely felt.
Cristiano Ronaldo established himself as one of the two best players in the world during his time at Manchester United, helping fire them to three Premier League titles and the Champions League before moving to Real Madrid and becoming one of the all-time greats.
But things could've panned out very differently, according to the late, great Gerard Houllier. Liverpool were tracking Ronaldo for a year but there was some dispute over his potential wages, with the young Portuguese apparently wanting a salary that would've been superior to that of Ballon d'Or winner Michael Owen.
Liverpool were understandably reluctant to agree such terms and then came a fateful day. United played Sporting Lisbon in a pre-season friendly and Ronaldo's performance was so compelling that the entire team told Ferguson to sign him.
That saw Ronaldo's price-tag more than triple and Liverpool weren't willing to match the new valuation. The rest, as they say, is history.News Now - Sport News