Middlesbrough winger Carlos de Pena has joined Real Oviedo on loan for the rest of the season.
The Uruguayan, 24, cost Boro £3m when they bought him from Nacional in 2015 but he has made just 10 appearances for the club.
He last played for the first team a year ago and has been playing in the U23s this season, unable to make an impact on boss Aitor Karanka.
Karanka admitted on Monday: "I couldn't bring out his best. He's a really good player and he's a really good kid."
Oviedo play in the second tier of Spanish football and are currently 10th in the league.
Austria U19 international Arnel Jakupovic has left Boro to join Italian Serie A side Empoli for an undisclosed fee.