The 17-year-old Liverpool player has been named in the squad to face Finland at Windsor Park on August 15, despite not yet featuring in a competitive game for the Reds.
“This is as much for Ryan’s experience as anything else and we don’t want to put any expectations on him that are unrealistic.”
The former Glenavon full-back signed a three-year deal at Anfield last summer and O’Neill feels he is one of a number of youngsters who could play a significant role in the future.
“Ryan’s a young player and we want to try and introduce more young players,” O’Neill said.
“This is as much for Ryan’s experience as anything else and we don’t want to put any expectations on him that are unrealistic.
“He played for the Under-21s last season and did very well. It’s a chance to bring him in and let him see what full internationals are about.
“It will be good for him to meet the players as well because some of the younger players will have a significant role to play in the next campaign.”
Northern Ireland play Russia in Moscow in a World Cup qualifier on September 7 and O’Neill is hoping they can make the limited preparation time count in this month’s friendly.
“This is a difficult game because there are club fixtures right until the Tuesday night,” he added.
“There’s a bit of co-operation required between the clubs and ourselves in terms of getting the squad together.
“Ideally we’d like the players for a little bit longer, but we’ll have them from the Sunday evening.
“It’s our last preparation game before we play the qualifiers and we’re looking forward to getting the players together again.”