While Phil Jagielka is sidelined, the Irishman is prepared to take any opportunities that may come his way.
Duffy told evertonfc.com: "I'm just learning every day for when the manager needs me - this is why I'm playing in these [Under-21s] games. It's important to get some match action so that if he needs to throw me in then I'm alright.
"It's a good time to be around the team and we still have a lot to fight for in the league. It's good to be around such quality players and I would probably learn more here than if I went out on loan.
"I'm happy to wait for my chance at Everton and hopefully that will be soon."