Middlesbrough chief Parnaby hails prospect Walker
"Aberdeen could well play an important part in his development and we've selected them carefully as the right club.
"Josh is a player who likes to play passing football on the ground.
"Aberdeen are a team that likes to pass the ball so Josh will have no problems adapting to their style of play.
"We're hopeful he will develop further as a player in terms of becoming stronger and a more complete player.
"We're hoping his spell in Scotland will see him flourish."