Kudus has been admired by Everton since the summer, when they wanted to bring the Ajax star in on loan to Merseyside.
A move then did not materialise, but Everton continue to remain interested in the midfielder, who has started the season impressively for Ajax.
Ajax took on Napoli in midweek in the Champions League and Kudus scored, but the Dutch champions were thrashed 6-1 by the Italian team.
Scouts from Everton were present at the Champions League match, with the Toffees continuing to monitor their summer target.