Academy youngsters Terrell Agyemang and Fenton John have each joined non-league clubs on short-term loans.
Former Manchester City midfielder Terrell has linked up with National League side Hartlepool United, while Fenton, also a midfielder, rejoins Northern Premier League outfit Morpeth Town.
The duo, who have each featured in an unbeaten start to the season for Boro's Under-21s, follow teammates Ben Beals and Jack Hannah in heading out on loan to cut their teeth in senior football.