Willian dismissed the prospect of a January move from Chelsea after his strike earned a 2-1 win over Newcastle.
Chelsea this week turned down an approach for Willian from Barcelona, who offered Malcom to the Blues as part of a proposed exchange deal.
Chelsea head coach Maurizio Sarri on Friday insisted it was “impossible” to lose Willian.
And the 30-year-old showed his value to Chelsea by scoring the goal which has given the Blues a six-point cushion over fifth-placed Arsenal in the race for Champions League qualification.
“My future is at Chelsea,” Willian told BT Sport.
Sarri afterwards repeated his view on Willian, who has 18 months remaining on his current contract, but Chelsea could be busy in the winter transfer window, nonetheless.
Cesc Fabregas completed his move to Monaco on Friday and Sarri wants a replacement but is uncertain if, or when, a new recruit will arrive.
Cagliari’s Nicolo Barella and Leandro Paredes of Zenit St Petersburg have been linked with moves to Chelsea.
Sarri’s need was emphasised against Newcastle as Jorginho struggled to dictate play.
The Italian said: “Today Jorginho was in trouble and on the bench there wasn’t a player for that position. I need an option for Jorginho.”