Sheffield United have intensified their efforts to sign South Korean full-back Seol Young-woo from Red Star Belgrade(Crvena Zvezda), with Serbian outlet MaxBetSport reporting that the Championship club are ready to table a €3 million offer, potentially rising to €4 million with performance-related bonuses.

The 25-year-old defender has emerged as a key figure in Vladan Milojević’s Red Star side since joining from Ulsan HD just over a year ago. Now, with Premier League ambitions firmly in mind, Sheffield United are hoping to lure him to Bramall Lane.

The Blades will send a scout to monitor Seol during Red Star’s Champions League third qualifying round first-leg clash against Lech Poznań on Wednesday evening. The South Korean is expected to return to the starting XI after serving a suspension picked up in the previous round against Lincoln Red Imps.

Red Star may have a decision to make, especially with Nikola Stanković recently returning to the club — a move some in Serbia interpret as preparation for Seol’s potential departure.

However, Sheffield United’s offer is still below the player’s €5 million release clause, meaning negotiations could prove challenging unless the English side are willing to raise their bid.

Seol has proven to be one of Red Star’s most reliable performers, not only operating as a right-back but also filling in on the left when needed. In 43 appearances for the Serbian champions, he has scored six goals and provided eight assists, including three in last season’s Champions League group stage — showcasing his value on the biggest stage in European football.

Red Star paid €1.5 million to Ulsan for Seol’s services last summer. He has since become a regular in the South Korean national team, earning 24 senior caps to date.

Should the transfer materialise, it would represent another significant departure from the Marakana this summer — albeit one that brings a healthy financial return.