According to Sky Sports Germany, Dortmund have no intention of letting the 25-year-old leave and will seek to offer him a new contract, doubling his current salary to an estimated at €5m-€6m per season.
The Germany international is set to enter the final two seasons of his Dortmund contract, with reports suggesting that Liverpool are prepared to offer more than €50m (£42m) for him.
Schlotterbeck has been a key player for the German side so far this season, starting all 36 of his games across all competitions, as well as providing four assists in his 3184 minutes on the field.
The centre-back’s fine form has gained the interest of Premier League leaders Liverpool, who are increasingly resigned to losing Van Dijk, 33, on a free transfer at the end of the season.
Van Dijk is one of three Liverpool stars who look set to leave the club in the summer, alongside talismanic forward Mohamed Salah and Trent Alexander-Arnold.
Arne Slot’s side will be hoping to put the disappointment of their 2-1 Carabao Cup final defeat to Newcastle with a win over rivals Everton after the international break.