Ryo has been added to Arsenal's squad for the Champions League Play-Off Round.
Earlier this month the Club submitted an A list (List A) and a B list (List B) of players, all of whom will be eligible for the Play-Off Round tie with Udinese.
A single change to the squad can be made after the date it is originally submitted and the Club have opted to add Ryo to List A.
Should the Club progress to the Group Stage of the competition, an updated List A will be submitted by September 1, which will apply for the remainder of the competition.
Under UEFA rules, Arsenal is eligible to register 25 players to List A for the Play-Off Round and an unlimited number of players to List B.
A player qualifies for inclusion in List B if he was born on or after January 1, 1990 and has been eligible to play for the Club for an uninterrupted period of two years or more since his 15th birthday.
Arsenal's Champions League squad:
Robin van Persie