But the tables might just have turned because, for Declan Rice, it could be the other way around.
Having been released by the Chelsea academy at the age of 15, the 22-year-old is now one of the best midfielders in the Premier League.
Rice played every game for England as the Three Lions reached the final of Euro 2020 - and now the box-to-box star has captained West Ham to third place in the top flight.
Suddenly, his £100million price tag over the summer, which Chelsea and Manchester United refused to pay, looks like a bargain.
And they'll have to pay more if the Hammers are even willing to entertain selling him any time soon.
But the Blues may take inspiration from the last time they paid over the odds to sign a midfielder from West Ham.
You know, the one who turned out to be arguably the best signing in their history.
In 2001, £11million was big money. At that point, the biggest deal done in the Premier League was Nicolas Anelka from Arsenal to Real Madrid for £22.5m.
There were questions about whether Rice was worth £100m last summer. Well, many didn't think the Blues were right to pay so much for Lampard.
The former Hammers midfielder struggled for affection at Upton Park, finding it difficult to shrug off suggestions of nepotism.
After breaking into the senior squad aged 17, Lampard faced accusations of favouritism from minute one, and it didn't help that his uncle, Harry Redknapp, was the manager, alongside his dad as the assistant.
Large sections of fans would taunt him about his weight and his connections at the club, to the point where it became oppressive and personal, even cheering as he broke his leg in 1996.
Still though, given he was never really that bad for West Ham, a pre-Roman Abramovich Chelsea were willing to splash the cash.
Aston Villa also made a £15m bid for Lampard and Freddie Kanoute, which was rejected by the Hammers.
Furious with the West Ham chairman Terry Brown for his treatment of his dad and uncle, Lampard quickly set his sights on revenge.
Chelsea chief executive, Colin Hutchinson, explained at the time why the club were so keen to land him. "We have been bringing the age down in the squad for the last year and people may think he is older because he's been around a bit but Frank is only 22."
As it turned out, Lampard was quite good at football and not, as some had harshly suggested, just a fat kid picked on nepotism.
He scored seven goals in 20 appearances against West Ham on his way to becoming the greatest goalscorer from midfield in Premier League history.
In the end, £11m turned out to be one of the biggest bargains in English football history.
Rice is adored by the Hammers faithful in a way that Lampard never was.
Ironically, it was during Lampard's tenure as Chelsea boss when the club were initially credited with an interested in Rice, as the Blues legend threatened to make himself even more unpopular in east London.
But, in case you haven't heard, West Ham are massive now - and maybe they'll keep this in-demand England star for themselves.