Chelsea have included a buy-back clause in Nathaniel Chalobah's sale to Watford.
The London Evening Standard says the Blues also stand to profit should the Hornets sell Chalobah elsewhere as they have negotiated a sell-on fee.
Chelsea wanted to hand the 22-year-old a new contract but as first revealed last month, the midfielder was looking to leave after making just 15 appearances last term.
Chalobah has joined Watford for £5.5million.
He had only one-year left on his current contract and Watford are believe to be thrilled at getting such a bargain.
Source: tribalfootball.com