The 23-year-old was the surprise omission for the World Cup qualifier in Slovakia, where England scraped a stoppage-time 1-0 victory.
"Ross can feel a little bit hard done by," said the midfielder, speaking at Everton in the Community's annual charity golf day.
"It's a tough job being England manager and Sam said it was a really tough decision for him but in terms of Ross now he needs to use that to help him improve and not get down about it but prove the manager wrong and get himself in the next squad.
"I trained with him and he didn't seem too worried about it. He's got that grit between his teeth that he's going to prove the England manager wrong so hopefully he can put in good performances with Everton to do that."