MIDDLESBROUGH are attempting to follow up the signing of former Barcelona goalkeeper Victor Valdes by luring Bundesliga winner Neven Subotic to the Riverside Stadium.

During an exciting day of transfer activity on Teesside, The Northern Echo exclusively revealed online that Borussia Dortmund defender Subotic had been to the Riverside for a tour and talks.

NEW: Middlesbrough in training - see gallery

That was followed shortly after by confirmation from the Premier League new boys that Valdes, one of the most successful Barca and La Liga keepers ever, had signed a two-year contract with Aitor Karanka’s side.

The 34-year-old boasts winning the Champions League, Spanish league, World Cup and European Championships on his CV and now he will battle to get his career back on track after an unsuccessful 18 months under contract at Manchester United.

Valdes has arrived as a free agent and will compete with Dimi Konstantopoulos and Tomas Mejias for the first team goalkeeper shirt ahead of the first game of the season against Stoke on August 13.

Karanka said: “You can't imagine how delighted I am because it's not usual to bring players like him to recently promoted teams.

“I'm really pleased because he is really committed. All the conversations we've had he knows why he is here and he is coming to add to what we have. He knows how strong this group is. It's a privilege for us to be able to bring a player like this to the club.”

Valdes becomes Middlesbrough’s fifth signing since clinching promotion back to the Premier League. Viktor Fischer, Bernardo Espinosa, Jordan McGhee and Marten de Roon had all joined before the former Spain shot-stopper.

But Karanka is not finished yet and Subotic, who won the German league twice under Jurgen Klopp in 2011 and 2012, is in line to follow them to the ambitious North-East club.

The 27-year-old, who has been tracked by a number of clubs in England and across Europe including Sunderland, is available for £8m. Liverpool, Arsenal and Stoke are three other Premier League sides looking to talk, although there are concerns he will struggle to get a work permit.

Dortmund gave him permission to miss training to talk to a club earlier in the day. 

The Serbia international, who walked away from his national side a few years ago after 36 caps despite being a prominent part of the Dortmund defence after joining from Mainz in 2008, is known to have visited Middlesbrough for talks and for a look around; he is also known to have been impressed by what he has heard and seen.

Karanka has played a key role in talking to his main targets and the head coach believes the transfer progress is a sign Middlesbrough are no longer ‘a project’ following the success in the Championship last season.

“We have really good players and for sure we are going to have calls from other teams to sign them,” he told the club’s website. “But we have to try to build the team as strong as we can.

“It’s nice when now we have meetings with other players to try to convince them [to sign]. Now we are not a project like we were last season or two seasons ago. Now we are in the Premier League.”

Following the arrivals of Valdes, Fischer, Espinosa and de Roon, with the possibility of Subotic joining too, Middlesbrough have made waves on the transfer front and the supporters are buzzing ahead of Saturday’s first pre-season friendly at York City.

But Karanka would still like to bring in more new signings from abroad and a new striker and right-back are known to be high on his list of priorities, particularly if he can pull off the Subotic signing.

The arrivals are likely to lead to outgoings, but Karanka wants to focus on those he can bring in first before he can make serious decisions on the calls he is fielding about the men other clubs want who he has at his disposal.