What have Dave Sexton, Gianluca Vialli, Roberto Di Matteo and Rafael Benitez got in common? They have all won a European trophy as manager of Chelsea.
Jose Mourinho has yet to do the same. It's one of the few holes in his hugely impressive CV and one that he is desperate to fill.
When the Portuguese returned to Stamford Bridge last summer, it was because he had unfinished business with the Blues.
Domestically he had delivered in his first spell as boss, winning two Premier League titles in his first two seasons at the club. There was also cup success, winning the League Cup twice as well as beating Manchester United in the first FA Cup final at the new Wembley.
But on the European stage he failed to make a final, twice losing to Benitez's Liverpool in the last four of the Champions League, in 2005 and 2007, much to his dismay.
Mourinho is desperate to put that right and he has the pedigree to do it.
It was in 2004 that he announced himself on the football world, guiding Porto to a stunning European Cup success, helping him land the Chelsea job a few weeks later and in 2010 he inspired Inter Milan to glory in the competition.
If he were to claim the continent's most prestigious prize once more, he would go level with Liverpool legend Bob Paisley, who won it three times as a manager (1977, 1978 and 1981).
The Special One may have to wait a year or two though because entering tonight's quarter-final second leg in London, his side trail Paris St Germain 3-1.
Chelsea have been here before. In 2012 they lost in Italy to Napoli by the same scoreline heaping pressure on then boss Andre Villas-Boas, who was sacked days later.
Di Matteo was in charge for the return and on a famous night at the Bridge, the Blues powered themselves to a 4-1 victory, after extra-time, and 5-4 aggregate success.
It was a result that laid the foundations for an astonishing run which somehow saw them beat holders Barcelona in the semi-finals and then Bayern Munich in their own Allianz Arena home in the decider.
It was destiny.
At the time Mourinho said how pleased he was. He meant it because of his genuine affection for Chelsea, but there will have been part of him wishing he had been managing the team that year rather than Di Matteo.
Tonight offers Mourinho the opportunity to produce some European history of his own...staying alive in this precarious situation would provide the players with that same 'anything is possible' confidence that lifted them to such great heights two years ago.
Chelsea need goals and unlike last week that means starting a striker in attack, be it the misfiring Fernando Torres or even Demba Ba, if Samuel Eto'o is unable to lead the line.
The Blues also need big performances from big players like Eden Hazard and Oscar, and although partly to blame for PSG's final goal last week, Frank Lampard, the club's greatest player, should start. He rises to occasions such as this.
Most important of all Chelsea require their usual solidity at the back, rather than the pitiful defensive efforts in the first leg which gifted the French side three goals.
Zlatan Ibrahimovic may be missing, but the excellent Ezequiel Lavezzi and Edinson Cavani will take advantage of any slips.
PSG are a force to be reckoned with. So is Mourinho.
He'll have the Blues ready for this one, knowing he will never feel complete until he has led them to European glory.