I was interested in the 'sue him' comment. Didn't think about it and with such a massive price tag, and only playing a couple of seasons of an eight year contract, that's an awful lot of shortfall and definitely should be sued. But it appears the Ukrainian Association of Football would be the accountable party, not the player who allegedly took the performance enhancing drug meldonium.

Sports lawyer Catherine Forshaw has stated that Chelsea could file a lawsuit against the Ukrainian Association of Football (UAF) over Mykhailo Mudryk's positive doping test.
"If Mudryk faces sanctions, Chelsea may consider terminating his eight-year contract depending on its terms. A four-year suspension would significantly affect the club financially.
"Chelsea could sue the UAF if Mudryk is charged and suspended, depending on where the fault lies. If others, such as Mudryk's support staff, are involved, Chelsea might pursue them legally.
"If Mudryk receives a suspension of over two years, Chelsea would likely terminate his contract rather than wait out the ban.
"If Mudryk is exonerated, he is unlikely to secure compensation for temporary suspension, as he remains responsible for substances in his body per Premier League and global anti-doping rules."
Forshaw added that Mudryk could sue liable parties if financial damages are proven and his innocence is established.