Barry says the playmaker is still young and just needs to be more chilled on the pitch.
"Ross is still really young and people sometimes forget that," said the former England midfielder.
"He had a fantastic season last season and the big test for any player is to keep performing week in, week out.
"It's very hard for any player to do that and Ross is on a big learning curve. His performance away at Young Boys last week was tremendous and like the team, he performed at a different level to he has at home.
"He just needs to relax a bit, play his normal game and his ability will come through."