Chelsea have completed the signing of Lyon right-back Malo Gusto for £26.3 million, with the 19-year-old spending the rest of the season back in France on loan.
Mykhailo Mudryk starred on debut as Chelsea and Liverpool played out to a goalless draw at Anfield in the Premier League on Saturday.
Chelsea have continued their spending spree after completing the signing of Noni Madueke from PSV Eindhoven.
Arsenal moved eight points clear at the top of the Premier League table with a 2-0 win over Tottenham Hotspur, while Chelsea returned to winning ways following their 1-0 win over Crystal Palace on Sunday.
Chelsea are "very close" to completing a deal for Shakhtar Donetsk striker Mykhailo Mudryk, the Ukraine club accounted on Saturday.
New signing Joao Felix was sent off on his debut as Chelsea's woes continue after they fell to a 2-1 defeat to Fulham in a London derby encounter on Thursday.
Chelsea manager Graham Potter praised the quality of new signing Joao Felix and believe the Portuguese forward could "make a difference" in the Blues squad.
Chelsea have officially completed the signing of Joao Felix on loan from Atletico Madrid for the remainder of the season.
Manchester City are set to face either Oxford or Arsenal in the fourth round of the FA Cup after cruising to a comfortable 4-0 victory over Chelsea on Sunday.
Pep Guardiola has urged Chelsea co-owner Todd Boehly to back under-fire boss Graham Potter despite their 4-0 defeat to Manchester City in the FA Cup third round on Sunday.