Metalist Kharkiv manager Miron Markevich has urged the club's owners to sell Taison to Chelsea.
Chelsea agreed to pay £12.4m before Christmas and thought the deal would go through without a hitch this month but Metalist had a change of ownership at the end of December.
Markevich said: “If he does not play with the soul and heart of Kharkiv, he is not with Metalist and it is better to let him go.
“Prior to the change of ownership of the club, there was an option for parting with Taison. At the same time, the new owner does not share this position and does not think that we must part with Taison.
“He has a clause in the contract, according to which, if any club will offer $20million [£12.4m] or more, we will be forced to sell him. If this happens, I would urge the owner to part with Taison. I am sure that I can, for that money, buy two players to replace Taison and it will only strengthen the team.”