The Hornets offered £10m plus veteran stopper Heurelho Gomes in exchange for the Bosnia and Herzegovina international, according to Daily Telegraph journalist Matt Law.
Begovic’s future has been subject of much discussion during the transfer window with Bournemouth hoping to sign him for £10m.
Antonio Conte was willing to let Begovic leave on the condition he landed a suitable replacement.
He recently publicly hinted at an exit and said: “I have spoken with the boss – we are quite open about it, he knows I am desperate to play, and that’s all it is really.
Watford contact tells me they failed with a bid for Asmir Begovic today – offered £10m plus Gomes but Chelsea said no #cfc
— Matt Law (@Matt_Law_DT) January 31, 2017
“If he can make it happen for me he will. That is something that is going to be sorted out in the next couple of days.
“I’m 29, 30 in the summer, and feel fantastic and in great shape. It would be a waste not to play and show people what I can do.”