Middlesbrough have agreed a three-year deal with Borussia Dortmund defender Neven Subotic.

The 27-year-old will join the Riverside club for £8million subject to a work permit.

Other clubs had initially turned down the chance to sign the Serbian owing to the fact he last played for his country in 2013 and believed a work permit would be too difficult to obtain.

Subotic signed for Dortmund in 2008, after following manager Jurgen Klopp from Mainz, and has since gone on to make 258 appearances for the Bundesliga club.

Middlesbrough have agreed a three-year deal with Borussia Dortmund defender Neven Subotic

Subotic has not represented Serbia since 2013 and so his transfer will be subject to a work permit hearing

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The Serbian was an integral part of the Dortmund side that secured back-to-back league titles in 2011 and 2012.

However, he is likely to see his opportunities limited next season following the arrival of Marc Bartra from Barcelona.

Middlesbrough have also agreed a contract with midfielder Gaston Ramirez, who is a free agent after leaving Southampton last season.

Ramirez had a successful loan spell at Boro, where he scored seven goals in 18 league appearances, to help Aitor Karanka's side gain promotion to the Premier League.

Middlesbrough have also agreed a contract with Gaston Ramirez, who left Southampton earlier this summer

Aitor Karanka has already added five new players to his squad ahead of the upcoming Premier League season

The 25-year-old's signing is also subject to a work permit hearing.

Ramirez stands a better chance than Subotic of having a work permit granted as he recently represented his national side, Uruguay, at this summer's Copa America Centenario.

Karanka has wasted no time in adding to his squad this summer, with Marten de Roon, Víctor Valdés, Viktor Fischer and Bernardo all joining the club since the start of July.

Middlesbrough defeated York City 6-0 in their first pre-season friendly and will next face Doncaster Rovers on July 16 as they continue their preparations for the upcoming Premier League campaign.