Chelsea owner Roman Abramovich would reportedly have to pay out a world record £37.5m if he chooses to sack manager Jose Mourinho.
The Portuguese coach's contract, which is due to run for another three years after this season, is worth more than £10m per year, according to the Daily Star.
Abramovich has publicly backed Mourinho to reverse the Blues' fortunes, but has paid out vast sums to unseat previous managers.
Luiz Felipe Scolari bagged £12.6m, Carlo Ancelotti was handed £6m with one year left on his contract, and Andre Villas-Boas was awarded £12m, only to waive some of the fee when he took over at Tottenham Hotspur.
Chelsea have endured a dismal start to their Premier League title defence, with last weekend's 3-1 home defeat to Southampton leaving them in 16th place in the table.