The Portuguese winger's two second-half goals ended Everton's unbeaten run and secured Chelsea's first Premier League clean sheet in nine months, though the result was overshadowed by a serious head injury to goalkeeper Emiliano Martinez.
Pep Chavarria is absent despite travelling to the Hill Dickinson Stadium, while Reece James begins rehabilitation after successful knee surgery.
The Arsenal manager says reducing up to 60 roles is necessary to keep the club moving forward, but the timing alongside his own new contract has drawn scrutiny.
The England midfielder has rejected contract offers at Bournemouth and the Cherries are now open to selling him in January if their price is met and Premier League survival looks secure.
Second-half goals from Timber, Eze and Saka swept Arsenal past a stubborn Lille side who had kept them at bay for an hour.
