The details of the clause have been reported by German newspaper WAZ, providing a clearer picture of the conditions under which the Austrian-born Bosnian coach could leave Gelsenkirchen.
Previous reports had put the potential fee between €5 million and €8 million, but the latest figures suggest the amount depends on the identity of the interested club.
English sides and Champions League participants would face the higher €6 million fee, while clubs outside those categories would have to pay €4 million.
Muslic remains under contract with Schalke until June 2028. According to the report, the release clause can only be activated next summer, meaning any club hoping to appoint him would need to wait until the relevant window.
That timing gives Schalke an opportunity to address the situation before the clause becomes available. The club are reportedly planning to open discussions with Muslic in the spring, with the intention of removing the release clause from his contract.
The move would be designed to protect Schalke from losing a coach who has made a strong impression since taking charge. Securing a new agreement without the clause would give the club greater control over his future and make it harder for outside teams to recruit him through a predetermined fee.
For now, however, the reported terms remain in place, and there is no indication that a club has formally moved to activate them.
The different fee levels could prove significant if interest develops from England or from teams involved in the Champions League. Those clubs would have to weigh the €6 million cost against the prospect of appointing Muslic, while other potential suitors would face a lower financial barrier.
Schalke’s priority will be to maintain continuity and begin negotiations before next summer. If the club can persuade Muslic to agree to revised terms, it could remove an important source of uncertainty around his position.
Until those discussions take place, the release clause remains a potential route for interested clubs to pursue the coach when the next summer window opens.