The club have completed the loan signing of highly-rated Luke Thomas from Leicester City.
The 22-year-old left-sided player links up with Michael Carrick’s squad until the end of the season.
A product of Leicester’s Academy, Luke brings plenty of experience despite his tender years.
He has already made almost 100 career appearances – 68 of which have come in the Premier League.
The player, who has represented England from Under-18 level to U21s, had initially joined Sheffield United on a season-long loan in the summer, but he returned to his parent club two weeks ago.
Boro boss Michael Carrick said: “We’re delighted to bring Luke to the club. He’s a good addition to the squad, he has plenty of experience, and he will bring a balance to what we have. We’re looking forward to working with him.”