Brentford had believed they were close to signing Mykhaylo Mudryk for just £20 million last summer
The Ukraine winger has completed a deal worth nearly five times that sum to sign for Chelsea this winger.
Mudryk has signed an eight and a half year contract with the Stamford Bridge club.
Per The Mirror, Shakhtar Donetsk were willing to sell for a much lower fee only six months ago.
However, Brentford could not negotiate personal terms with the player and his agent.
Arsenal are another team who missed out on Mudryk, having chased him throughout the January transfer window.