The 23-year-old completed the formalities of his switch at Rockliffe on Thursday morning. 

A left-sided player – either full-back or further forward – McQueen is a product of the Southampton youth systems and played alongside former Boro loan man Calum Chambers in the Saints Academy. 

He already has almost 50 appearances to his name – 20 of which have come in the Premier League for Southampton. His first senior start came in the San Siro in the Europa League almost two years ago and his first top-flight start was against Manchester City a few days later. 

McQueen also spent time on loan at Southend earlier in his career was also capped once by England at U21 level. 

He becomes the club’s sixth summer recruit, joining permanent signings Aden Flint, Paddy McNair, and Andy Lonergan, and loan men Jordan Hugill and Mo Besic.

McQueen will wear the no.14 shirt for Boro this season.