Chelsea reportedly face wasting as much as £2.1m courtesy of Joao Felix's red card against Fulham on Thursday night.
Earlier this week, Chelsea were proactive in getting a straight loan deal over the line for the Atletico Madrid forward in order for him to be available for the short trip to face their West London rivals.
For 58 minutes, the 23-year-old produced an encouraging display, injecting some much-needed energy into a Chelsea attack which has often looked lethargic this campaign.
However, the Portugal international was dismissed shortly before the hour mark for a mistimed lunge on Kenny Tete, making contact just below the defender's knee.
There was no doubt that the decision was the correct one, and Chelsea subsequently went on to lose 2-1 having been level with Felix on the pitch.
The playmaker will now serve a three-match suspension, starting with another London derby versus Crystal Palace on Sunday afternoon.
Felix will then miss the trip to Anfield to face Liverpool, as well as the return fixture against Fulham which takes place at Stamford Bridge on February 3.
According to the Daily Mail, Chelsea now face shelling out over £2m on a player who will be unavailable for almost a month.
The report claims that Chelsea are effectively paying £714,286 per Premier League game during Felix's six-month loan spell at the club.
Atletico were not interested in allowing Chelsea or any other interested team to include an option to buy in any proposal, and it is alleged that Chelsea agreed to pay a loan fee of £9.7m.
With Chelsea being out of the FA Cup and EFL Cup, Felix is not due to be back in contention until the trip to West Ham United on February 11.
The first leg of the Champions League tie with Borussia Dortmund follows four days later, before Felix will be in line to make his Stamford Bridge bow versus Southampton on February 18.
Chelsea are currently considering whether to make further additions in the final third with Borussia Monchengladbach's Marcus Thuram being heavily linked with the club before Felix's moment of madness.
Other alternatives at the club, such as Raheem Sterling, Christian Pulisic and Armando Broja, are ruled out in the short and long term. body check tags ::