Chelsea are reportedly withholding the full £9m compensation payment owed to Antonio Conte due to their former manager's treatment of Diego Costa.
The 49-year-old was sacked by Roman Abramovich last July following a two-year spell in charge.
Conte, who won the Premier League and FA Cup during his time at Stamford Bridge, still had one year to run on his contract when Chelsea relieved him of his duties.
Despite having a clause in his contract that guaranteed him a large payoff, The Times reports that Chelsea will look to avoid paying the severance package on the grounds that Conte's conduct in his second year in charge was questionable.
At a tribunal hearing that started on Thursday, it is claimed that the Blues put forward their argument for withholding the £9m sum, arguing that the Italian forced Costa to first go on strike and then force through a move to Atletico Madrid following a public falling-out.
Costa was sold back to Atletico for £57m, but Chelsea allegedly feel that his valuation dropped significantly after his quarrel with Conte.