The 23-year-old will be available on a free transfer next summer with his contract set to expire, but interested parties are able to open up discussions from January onwards.
According to Bild, Schalke are adamant that they will not lose another key player for nothing after seeing Joel Matip move to Anfield on a free transfer this past summer, but they may not have a choice if the player himself decides on a move elsewhere.
Kolasinac is a familiar name around Europe as he has impressed during his time with Schalke, but the report goes on to suggest that his agent is urging the Bundesliga outfit to offer him a new and improved contract and is perhaps using the speculation to their advantage.