The striker, who is on loan from Barcelona, scored the opening goal and put in an impressive display as the Toffees romped to a 4-0 win over Stoke City at Goodison Park on Saturday.
"We have seen it all season in training but he's had to be patient and wait for his chance because a lot of other players have been doing well too," Barry told the media. "He is so difficult to mark one on one, he loves getting at players and has a lot of pace and he made it difficult for his full-back.
"You can give yourself a yard but he has the pace to make it up. He will be difficult to play against and the more he gets his chances I am sure he will improve again. Anyone who has come through [Barcelona's] ranks is going to have some real quality about them: the fans are starting to see that now and I am sure there is more to come.
"There is still a lot that Gerard will have to learn coming up against different opposition but it's been a fantastic start for him."
Everton face Manchester United in the Premier League on Wednesday.