Gaston Ramirez has completed a transfer from Southampton to Middlesbrough, where he will remain on loan for the rest of the season.
The Uruguayan midfielder, whose contract with the Saints expires at the end of the season, has struggled for game time under manager Ronald Koeman.
The 25-year-old had recently been tipped to join the Championship side and now it has been confirmed by both parties.
Via the club's official website, Southampton's executive director of football Les Reed said: "We would like to wish Gaston all the best at Middlesbrough and with the opportunity to play regular first-team football for a club that is pushing for promotion to the Premier League."
Boro boss Aitor Karanka told his club's website: "I am really pleased. He is a really good player who knows the league and the country. He has international experience and has played in the World Cup. He is another good player for us.
"He is the kind of player who wants to join us and that shows he is committed to us. He has played in the Premier League and I think it is important to bring in players with this kind of experience."
Ramirez, who made 22 Premier League appearances for Hull City during a loan spell last season, has scored eight goals in 55 appearances for Southampton.
