Schalke sporting director Christian Heidel says decision on Leon Goretzka to be made in January

Schalke have done all they can to convince midfielder Leon Goretzka to stay beyond next summer, sporting director Christian Heidel has said, hinting that it is unlikely that they will be able to hold on to their prized asset.

The Schalke midfielder has entered the final six months of his contract and has refused to sign a new deal so far. He can begin talks with clubs outside Germany and even agree a pre-contract for a free transfer in the summer. Bayern Munich are favourites to sign the midfielder and were reported to have already had an agreement in place for the German.

However, the reports have been dismissed by his agent Jorg Neubauer, keeping the likes of Liverpool, who were reported to be favourites at one stage, still in the race for the German. According to German publication Bild, the Reds manager Jurgen Klopp has convinced the Merseyside club to bring the 22-year-old to Anfield adding to the arrival of Naby Keita from RB Leipzig next summer.

Neubauer told Sport 1: "When a decision has been made, Leon and I will first inform Schalke."

Schalke have offered Goretzka a new deal worth €12m a year (£10.6m, $14.4m) as they look to keep him at the Veltins Arena, but the player looks to have made up his mind to move on in the summer. However, Heidel has revealed that they will not increase their offer and a decision will be made on the German well before the end of January.

Heidel told Funke Mediengruppe, as quoted by ESPN: "It will not be long before a decision is announced, and it will not drag out until the end of January. Schalke cannot offer any more nor do any more than we already have.

"Leon wanted to wait and see how Schalke's sporting development went. It's been six months. We are in the best possible position in the league table behind Bayern and have reached the DFB Pokal quarterfinals."

Schalke are doing well in the Bundesliga, currently second in the table, 11 points behind Bayern. They are well on course for a Champions League finish and losing their star player midway through the season would be a huge blow to their chances of entering Europe's top tier.