The club has completed the signing of Fulham goalkeeper Marcus Bettinelli on a season-long loan.
The 28-year-old is a double promotion winner with the Cottagers and brings a wealth of experience, having clocked up over 200 career appearances.
Bettinelli’s arrival gives Boro boss Neil Warnock increased competition for the goalkeeping slot as he looks to shape his squad for the new season.
The former England Under-21 international becomes Boro’s second signing of the summer, following Grant Hall into the club.
A delighted Warnock said: “I’m really pleased. I’ve been tracking Marcus since he first got into the team at Fulham a good few years ago and when the opportunity arose to bring him here, I was quick to the call.
“He’s a good lad, he’ll fit in well and speaking to him, I’ve been really impressed by his attitude and his desire to play for us.”