Chelsea boss Graham Potter spoke with Mykhaylo Mudryk directly to get the deal over the line last week.
The Shakhtar Donetsk star is in London today for a Chelsea medical and will attend their clash with Crystal Palace at Stamford Bridge.
Italian transfer expert Fabrizio Romano says Potter played his role in helping Chelsea beat Arsenal to Mudryk's signing.
Potter called the player several days ago to lay out his plans for the winger and also Chelsea's long-term project.
It's reported Chelsea will pay €70 million for Mudryk, which could rise to €110 million including bonuses.
It is expected that the player will sign a contract until 2030.