Chelsea's squad has been rocked by the news that Mykhaylo Mudryk has tested positive for a banned substance and faces a ban of up to four years.
The Ukrainian has struggled to settle in the Premier League since completing an £88.5million move from Shakhtar Donetsk nearly two years ago. But he has been a valuable squad player for Enzo Maresca this season, featuring regularly in cup competitions and scoring three times in the Europa Conference League.
Mudryk's absence - if it extends beyond the next few weeks - would shake up the balance of power on Chelsea's left wing. Fortunately for Maresca, the club already has an agreement in place for a permanent solution.
Jadon Sancho was signed on loan from Manchester United during the summer, and he has chipped in with five goal contributions in 10 Premier League games since.
Chelsea's squad depth could have been hit hard if Sancho was to return to United at the end of the season while Mudryk serves a potential ban. But Blues chiefs had the nous to include an obligation-to-buy clause in their move for Sancho, meaning a permanent transfer for between £20million and £25m has already been agreed.
Negotiating that in the summer, when Sancho's stock was low, could prove to be a shrewd move by Chelsea chiefs. Without the clause, United would be able to draw more money out of them in the knowledge that, with Mudryk out, the Londoners would be desperate for a left-winger.
Alongside Sancho's permanent move, deals have also been agreed for teenage superstars Estevao Willian and Kendry Paez, who will join in the summer. The only question is in what position that trio will play, given they can feature in multiple attacking roles.
What it does mean for Maresca is that Chelsea do not necessarily need to go out and recruit if Mudryk is hit with a lengthy ban. Pedro Neto can also play on the left, so between the options at the manager's disposal, there are more than enough candidates to fill the spot in the Premier League and in cups.
With that being said, Maresca would naturally prefer to retain Mudryk. The 23-year-old claims to have no knowledge of the substance found in his urine sample and has vowed to try and get to the bottom of it.
He said: "This has come as a complete shock as I have never knowingly used any banned substances or broken any rules, and [I] am working closely with my team to investigate how this could have happened."