Winger Muzzy Carayol has joined Huddersfield Town on a season-long loan.
The 26-year-old, who made his debut for Gambia during the summer, completed the formalities of his switch on Thursday.
Carayol hasn't featured for Boro since suffering an ACL injury in March 2014, but he did make five appearances on loan at Brighton last season and joined Aitor Karanka's squad during pre-season.
Karanka confirmed last week that he expected the player to leave on loan and he said: "He came to see me and asked about leaving to play, and I completely understand that.
"We've been trying to find the best place for him to play because he's a really good player and one who needs to recover his confidence.
"He needs to be an impact player so for this reason Huddersfield could be a good place for him and if he's happy, we're happy."
Huddersfield have won one of their opening four games in the Sky Bet Championship.