Fairly often in professional football, paths re-collide which will trigger either fondness or ill-feeling between two individuals - or perhaps a simple case of what might have been.
It's been over 15 years since Jose Mourinho worked with Scott Parker during his first stint as Chelsea boss, in a season which will go down in history from start to finish.
From the famous 'special one' announcement on his first day in charge to a then-record points tally of 95, the Portuguese's introduction into English football was brilliantly eventful yet Parker, rated as one of England's brightest midfield prospects at the time, was one who simply fell by the wayside.
Admittedly, the midfielder was signed by Mourinho's predecessor Claudio Ranieri in January 2004, five months before upheaval at the Bridge, for £10m.
But at 24, Parker was entering the prime years of his career, following a career-start at Charlton which saw him thrive under Alan Curbishley in a deep-lying role and make his England debut, in November 2003.
Yet, as Ranieri was replaced by Mourinho, so Parker saw his first-team opportunities limited to a handful of chances - and even then his fitness let him down.
Parker was under no illusions - with Claude Makelele one of the most effective defensive midfielders in Europe at the time and Tiago signed that summer to play alongside him, the England international was an understudy. A back-up. A reserve.
He started just once in the Blues' opening ten league games - a 4-0 win against Blackburn - before a few Champions League outings as Chelsea topped their group.
Mourinho, with an array of talent as his disposal, was aware of Parker's continued frustration at being left on the sideline, saying: 'I can accept the player is not happy when he is not playing... Parker is a top professional and is working every day absolutely fantastically.'
But in mid-December, having come on as a substitute, disaster struck against Norwich as Parker broke his foot. Ten weeks later, as he neared the end of his rehabilitation, he broke his foot again.
And that was very much that - not just for the season but for Parker's Chelsea career. He did not play again for the club, as the Blues won the League Cup and the Premier League, though he did pick up a league winners' medal and joined in the title celebrations.
But Parker was not interested in being someone's replacement. In the summer of 2005, he quite happily parted ways and moved to Newcastle for £6.5m.
Speaking shortly after moving up north, Parker said: 'I didn't play a lot there, and when I did, especially under Mourinho, I thought I did well. But it wasn't meant to be.
'For one reason or another the manager didn't fancy me.'
Both moved on with their careers, with Parker having a distinguished conclusion to his career hopping from one London club to the next, while Mourinho won a glut of trophies across Europe.
Soon after taking over as Fulham's caretaker boss in 2019, Parker spoke admirably about Mourinho's managerial attributes: 'Very honest, ruthless at times, certainly you need to have that about you. He had the ability to make you feel ten feet tall or make you feel like you'd done the worse thing in the world.
'There was no middle ground in that sense. His communication with people at that time - making people feel a million dollars and getting the right people around him. Obviously everything else says a lot about him, a winner.'
Now though, the pair will collide again in a hastily-arranged Premier League encounter.
A game originally scheduled for December 30 but postponed due to a Covid outbreak at Fulham, it has been dramatically shoehorned into this week's spate of Premier League games, much to the annoyance of the Fulham boss.
Battling for survival in the relegation zone, with Mourinho having title aspirations at the other end of the table, the pair could not have more contrasting goals this season.
But don't count out Fulham at the Tottenham Hotspur Stadium - they held Liverpool to a draw earlier this season and perhaps should have come away with all three.
They've also lost just once in their last six league games - against Man City - with Parker's side who were deemed by some (Jamie Carragher) as 'dead certainties' for the drop showing some much-needed spirit in this frenetic part of the season.
For Parker, coming up against Mourinho remains a tantalising test of his managerial abilities: 'It only felt like yesterday when I was a player under Jose and now I'll stand in the technical area with him, albeit a few years under him in terms of being in this job, so his experience is far superior.
'It is an occasion I am relishing and looking forward to and I can't wait to meet up with him again and get my team to pit their wits against a very good opposition.'
The mutual respect is clearly still there. Fondness or ill-feeling? Neither, on this occasion. That is, until kick-off, when both will be scrapping for whatever they can on the touchline.