Duffus is targeting a regular starting spot for Everton Under-21s after helping the Under-18s win the league title last term.
He told evertontv: "It was a great experience winning the league with the Under-18s and playing often in the Under-21s was good as well.
"I really enjoyed last season.
"I can't wait to get back on the training ground. There's a bit of competition.
"I want to play regularly for the Under-21s and maybe even go out on loan. I'm not sure but I have to keep working hard and see what happens."
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