Aitor Karanka is reported to be looking for a new number one goalkeeper with Belgian stopper Matz Sels among the names being considered.
Middlesbrough won promotion back to the Premier League last season and are looking to improve their squad ahead of the 2016-17 campaign.
Reports suggest veteran Greek keeper Dimi Konstantopoulos will be the club's second choice for their return to the top flight, with several goalkeepers linked with a move to the Riverside over the summer.
Sels, also linked with Southampton, Everton, West Ham, Swansea and Bournemouth, is the latest name in the frame.
HITC Sport report Boro are leading the chase for the 24-year-old, who was part of Belgium's preliminary Euro 2016 squad but missed out on selection.
Sels has three years still to run on his current deal with Ghent.
Konstantopoulos may be 37 years old but the former Hartlepool United played a key role in Boro's promotion, playing every game in the league.
Karanka, though, is reported to be keen to strengthen that area of his squad, with former Barcelona star Victor Valdes also on the list of rumoured targets.
Valdes, 34, is available on a free after his contract at Manchester United expired