Jose Mourinho will arrive at Old Trafford as an away coach for the sixth time on Tuesday, but on future visits, he will hope to take a seat in the home dug-out.
It is thought that the position the Real Madrid manager covets above all others is the one currently occupied by his Manchester United counterpart Alex Ferguson, and Ferguson appears to support his candidacy.
Mourinho's first trip to Old Trafford as a manager, in March 2004, saw him embark on a provocative dash down the touchline after a last-minute goal by Costinha enabled Porto to knock United out of the Champions League.
Three months later, after guiding Porto to victory in the competition, he arrived at Chelsea and his arrogant posturing quickly raised Ferguson's hackles.
"I remember his first press conference and I thought: 'Christ, he's a cocky bas****, him,'" the Scot recalled in a British television documentary last year.
"He was telling the players: 'Look, I'm the special one, we don't lose games.'"
Mourinho's stunning success at Chelsea gave Ferguson even more reason to rue the Portuguese's arrival in English football, but the initial enmity gave way to deep mutual respect.
Asked if Mourinho could one day replace him at Old Trafford, Ferguson replied: "He can manage anywhere, absolutely.
"I'm not going to put any forecasts on what is going to happen at this club. I won't last forever but Jose can manage anywhere, there is no question about that."
Mourinho, 50, has made his desire to succeed the 71-year-old Scot common knowledge, but he toed a diplomatic line last month when asked if he was the man to replace Ferguson.
"I don't believe so," he said. "I think we have to end our career at the same time. Him at 90 and me at 70."
Mourinho remains one of only three men to have won the European Cup with two different clubs - Porto and Inter Milan - but his stock has fallen this season.
Madrid took last season's Spanish league title in imperious fashion but the wheels have fallen off their juggernaut in the current campaign, with Barcelona 13 points clear of their arch rivals in La Liga.
Sporting failure has been played out against a backdrop of changing-room tension, amid reports that Madrid's senior players have grown tired of their manager's limelight-hogging antics.
Mourinho is widely expected to leave the Bernabeu at the end of the season, although his stock has risen in recent weeks after back-to-back wins over Barca in the Copa del Rey and the league.
Hopes of delivering the 10th Champions League crown that Madrid crave, however, were compromised by the 1-1 draw at home to United in the first leg of their last-16 tie.
Mourinho's campaign for the United job has not been helped by the emergence of dissenting voices from within the Old Trafford hierarchy.
Club legend Bobby Charlton broke ranks to criticise the Madrid manager last year, apparently contradicting Ferguson's assertion that Mourinho would be a strong candidate for the role.
Asked about the 2011 incident that saw Mourinho poke Barcelona's then assistant coach Tito Vilanova in the eye, Charlton told The Guardian: "A United manager wouldn't do that.
"Mourinho is a really good coach, but that's as far as I would go really."
Peter Schmeichel, widely considered United's greatest ever goalkeeper, has echoed Charlton's concerns.
"He will not be the successor (to Ferguson)," the Dane told Spanish newspaper El Mundo Deportivo.
"He's a great candidate for his qualities as a manager but the club doesn't want all the things that come with him."
Mourinho has another opportunity to remind United of his managerial gifts on Tuesday, but his path to the Old Trafford hot-seat no longer looks quite as straightforward as it once did.