Kudus scored in last night's Champions League defeat at Liverpool.
The Daily Express says Blues boss Frank Lampard still retains an interest in the Ghana international and will be monitoring his situation in the Netherlands, but there are already fears that the Blues missed the boat by failing to land the star this summer.
Everton's summer bid of around £15million is regarded as already being a fraction of the player's value.
The attacking midfielder has played a huge role as Alfred Schreuder's side sit top of the Eredivisie with six wins from six.