A one-club man is defined as a sportsperson who, well, spends their entire playing career at the same club.
It's pretty self-explanatory.
In a world of players being labelled as 'journeymen' or 'mercenaries' with ever-inflating wage packets found elsewhere, we rarely find a player that is willing to dedicate what can be an 18-year career to the same team.
While few players can claim this title - including Tony Adams, Carles Puyol, Francesco Totti and Ryan Giggs - some fall just narrowly short.
It could be that their ageing legs were no longer serviceable to maintain the standards of their club, or they always had a secret yearning to play for a specific club. Maybe they couldn't pull their eyes away from one final pay-packet. In the more upsetting cases, some were simply not ready to accept that their playing days were over.
Players that were loaned out before the age of 22 for the sake of development will not be included. For example, Philipp Lahm had a two-year loan with Stuttgart between the ages of 19 and 21 but was always on Bayern's books.
With the rules established, let's get into it.
10. Daniele De Rossi
When AS Roma snapped up a plucky 17-year-old striker named Daniele De Rossi from Ostia Mare, no one could have predicted the future he would have at the club.
They quickly converted De Rossi to a holding midfielder and he established himself in the squad early on, making his debut in the Serie A in the 2002/03 season before earning his first cap for Italy just a couple of years later in a 2-1 win over Norway in a World Cup qualifier.
He even scored in the aforementioned game.
At club level, he would have an illustrious career in the Italian capital. Following Francesco Totti's transition to a super-sub role, Daniele De Rossi naturally inherited the captaincy.
The 117 capped man currently has the second-highest total appearances in Roma's history with 616 appearances in all competitions over his 17-year association with the club, during which he won 2 Italian Cups, 1 Italian Super Cup and 1 World Cup.
However, despite being a Roma icon, De Rossi never hid his love for Boca Juniors, electing to play for them before retirement. During a six-month stay with the Argentinian outfit, he made just 7 appearances, announcing his retirement in January 2020.