It is one of the signings of the Premier League era, one that ranks up there with the acquisition of Thierry Henry by Arsenal or Roy Keane by Manchester United. For all the money that has been thrown around by Roman Abramovich in the last nine years, Chelsea have probably never spent a better £11m than that which they paid for Frank Lampard almost exactly 11 years ago.
To put it in perspective, that same summer of 2001, Sir Alex Ferguson spent around £29m on Juan Sebastian Veron, long since gone and little more than a peripheral figure in the history of English football's last two decades. If Ferguson had decided to buy Lampard from West Ham, how differently might the history of the league – and the history of Chelsea – have panned out since then?
It is one thing to make a brilliant signing who turns into a key figure in the life of a team, it is another to acquire arguably the greatest player in the club's history. Chelsea have Peter Osgood, Gianfranco Zola and, of course, John Terry but if it is Lampard who raises the European Cup above his head at close to midnight in Munich tomorrow it will be hard to argue with the premise that he is Chelsea's best ever.
Just look at the record. Tomorrow will be Lampard's 558th appearance for Chelsea, all but 36 of them have been starts. In that time he has scored 186 goals for the club, just 16 shy of Bobby Tambling's record. He has three league titles, four FA Cups and two League Cups – just one short of Terry who has an extra FA Cup winners' medal from 2000. The Champions League would give Lampard the full set.
"I would love to win it," Lampard said this week. "I've said before, even if we don't win it, I'd have no regrets looking back. I'm very pleased and proud of the career I've had here. I've been very lucky to be at a great club and win a lot of things. But in terms of the full set on the table, it would be just that. You can't hide away from that."
Lampard was speaking earlier this week at Chelsea's Champions League final open day ahead of tomorrow's game against Bayern Munich, an interview conducted in a windswept, rainswept marquee on the edge of one of the Cobham training pitches. Lampard is one of the few who can still remember the days when the club trained on the Imperial College pitches at Harlington under the Heathrow flightpath, a wind-buffeted patch of land so ill-suited for elite sport that even current tenants Queen's Park Rangers are moving.
For Chelsea supporters, the relationship with Lampard has always been one of uncomplicated adoration but he has one year left on his deal and it is not inconceivable that tomorrow's game could be his last. The long, lucrative contracts on offer in China's professional league will be a temptation but then it would surely be difficult to leave Chelsea having finally won the Champions League.
Would this be the club's greatest moment? "I don't know really, I don't want to write us off in future years," Lampard said. "But every year we get asked the same questions: 'Is this the year? How inspired are you by the failures of years before?' And every year we have failed obviously because we haven't done it. We are one step closer to making it. Every year that goes past without winning makes it even more [pressurised]. The fact we are in the final is a great incentive."
Without the suspended Terry, Branislav Ivanovic, Ramires and Raul Meireles, and with injury concerns over Florent Malouda, this is a tall order for Chelsea. "[To win it] would be the greatest achievement," Lampard said. "We have four players out who have been some of our best performers of the season. It would be a huge achievement but I think every step has been a huge achievement – the Barcelona game and the turnaround from Napoli.
"We were struggling. It's not just because I was sitting watching from the outside. You could see that. You would not have looked ahead and seen this. I'm experienced enough to know things can change; but on that night I don't think any one of us thought it. We were despondent in the dressing room afterwards. The home game [a 4-1 win] was the major turning point."
The 3-1 defeat in Naples on 21 February was a low point for the club, but particularly for Lampard who was left on the bench by Andre Villas-Boas. Watching that night, could he have imagined that in little less than three months he would be contemplating potentially his greatest night ever as a Chelsea player?
"Maybe it was one of the lower times. But you learn through these things. I knew I wouldn't play 160 games consecutively (164 was his record-breaking number of consecutive Premier League games) all the time. These records don't go on forever. But it was tough at times for me when I wasn't in the team and frustrated individually.
"I sat back at times and got the hump indoors but I tried to carry on working hard and in the end it has turned around personally; but not quite to the full extent yet. If we win the final then I can probably answer that better."
Lampard is one of the survivors from the defeat to Manchester United on penalties in Chelsea's only other Champions League final appearance, in 2008, a game in which he scored. There is also the issue of qualification for the Champions League next year, with Chelsea having finished sixth, which Lampard described as a sideshow but conceded was at the back of the players' minds.
There is much at stake for Chelsea tomorrow but who would have thought, 11 years ago, he would have ended up here? In his autobiography, Lampard recalled his amazement when the Chelsea crowd first sang his name just for hitting a good pass. At West Ham, where the support had taken against him, it never happened. Four years after he joined Chelsea, he was named the second-best player in the world by Fifa. Winning tomorrow would top it all.