Chelsea have a unique ownership structure, wherein the club’s debt (about £1.3 billion owed to Abramovich) has been converted to debt held in a holding company, Fordstam Limited. While on one hand, the debt exposure towards related parties is significant, on the other, Chelsea have no interest-bearing financial debt owed to other parties, such as financial institutions. This bit of financial hand-waving means that Chelsea, as a club, are essentially debt-free, though Abramovich could theoretically call in the full amount owed, which could lead to an interesting situation. Though in practice would essentially mean he’s selling the club and the new buyer would have to fulfill that debt.
https://fanbanter.co.uk/ranked-premi...biggest-debts/
It could get interesting if Roman was subject to sanctions and decided to pull the plug in an act of revenge, but so far he's never shown any desire to harm or abandon Chelsea. I don't get the feeling he would want that to be his legacy.