Chelsea are hopeful of beating Arsenal to the signing of Mykhailo Mudryk after positive talks with Shakhtar Donetsk over a deal for the Ukraine winger.

Arsenal remain favourites to sign Mudryk, whose preference is to join Mikel Arteta’s side, but their first two offers have been rejected. The delay has presented Chelsea with an opening and, having met Shakhtar officials in London this week, they are ready to push on with a move for the 22-year-old.

Chelsea, who have been accused by Benfica of acting disrespectfully during their pursuit of the Argentina midfielder Enzo Fernández, have been left with the impression that £60 million ($71 million) plus £20 million ($23 million) in add-ons would land Mudryk. Arsenal’s latest offer was £44.2 million ($52.4 million) plus add-ons.

Arteta will have to decide whether to maintain his interest in Mudryk if Chelsea have an offer accepted. The reality for Chelsea is that the player would select Arsenal if presented with a choice between the London rivals.

Nonetheless Chelsea, whose January spending continued with the £33.6 million ($40 million) signing of the Monaco centre-back Benoît Badiashile, are prepared to use their financial clout and test Arsenal’s nerve. The club’s owners, Todd Boehly and Clearlake Capital, are keen to improve Graham Potter’s squad after a disappointing run of form.

The accusations relating to Fernández were made on Thursday by Benfica’s manager, Roger Schmidt, who said the Premier League club had unsettled the World Cup winner and changed the basis of discussions.

Chelsea have made Fernández a priority target. There have been days of talks and Fernández has told Benfica he does not want to play for them again but Schmidt insisted a deal was possible only if Chelsea paid the World Cup winner’s release clause, understood to be €120 million (126 million).

“There’s a club who want our player,” Schmidt said. “They know we don’t want to sell the player. They try to get the player on their side and they know that they only can get this player when they pay the clause. So it’s a very clear situation. What the club is doing who want to buy Enzo is disrespectful against all of us – against Benfica – and I cannot accept what they are doing.”

An angry Schmidt added, “So to make the player crazy and then to pretend they can pay the clause and later they want to negotiate, I think it’s not what I understand about a good relationship between clubs who maybe want to discuss about the player.”

Fernández has angered Benfica by returning to Argentina without their permission as he pushes for the move. Benfica would like to keep the 21-year-old until the summer and Chelsea maintain they do not want to overpay and will walk away if a deal cannot be agreed.

Lavish spending under Boehly and Clearlake continued with Badiashile signing on a seven-and-a-half-year deal. He is the third centre-half bought since the end of last season, after Kalidou Koulibaly and the injured Wesley Fofana. Badiashile is Chelsea’s second January acquisition, after striker David Datro Fofana.

• The Guardian report