Schalke have entered the race to sign Frankfurt right-back Sebastian Jung, according to Kicker.
Jung, 22, has been one of the key players for the Bundesliga surprise package this season. The full back has been one of the few Bundesliga players to play all 17 games from start to finish, scoring one goal and earning himself a place in the Germany squad in November 2012.
He is on a contract until 2014 at Frankfurt, but a release clause could allow him to leave the club for €2.5 million at the end of the season.
On Monday, Kicker reported that Schalke have become the latest team to enter the race for Jung. The Germany Under-21 international had recently been linked with VfB Stuttgart and VfL Wolfsburg.
The Royal Blues are seeking a right back, with Japan international Atsuto Uchida, 24, being the only experienced option in their current squad.
Centre-back Benedikt Howedes and defensive midfielder Marco Hoger have been mooted as possible replacements for Uchida. Schalke general manager Horst Heldt, however, refused to comment on a possible Jung transfer on Sunday.
Meanwhile, Marco Hoger, 23, has extended his stay at Schalke for another two years by signing a contract extension until 2016. "He is versatile and unbelievably hungry," Heldt said. "He has developed well and can step up even more."