Middlesbrough have re-signed Kenneth Omeruo on a season-long loan from Chelsea.
The defender spent the second half of last season at the Riverside, playing 14 times, before going on to play four games for Nigeria at this summer's World Cup.
Head coach Aitor Karanka told Boro's official website: "Kenneth is a very important player to us.
"He's someone I love to have with us because he's a player who came here from Chelsea and his mood was always perfect.
"He was always happy and fighting for his position.
"He was handed the opportunity to play in the World Cup and he is now coming back to us a better player."
Omeruo joined Chelsea in 2012 after coming through Standard Liege's academy. He was loaned to Dutch side ADO Den Haag for the 2012/13 campaign, where he made 36 appearances.