The Cameroon international has stalled on a new deal with the German club as he seeks a new challenge after 16 years in Gelsenkirchen.
Schalke centre-half Joel Matip is set to join Liverpool on a free transfer.
A deal has already been agreed in principle with the Cameroonian international.
Matip, 24, is out of contract in Gelsenkirchen, and wants a new challenge.
Jurgen Klopp has been an admirer since his time as Borussia Dortmund boss, and will add the 6’3” defender to his backline at the end of the season
The Reds chief has signed Steven Caulker on loan until the end of the season, after seeing his FOUR senior centre-backs all struggle with injury.
But Caulker's arrival from QPR is seen only as a short-term measure and he will leave Anfield at the end of the season.
Matip, who has 27 caps for his country, was wanted by Schalke to pen a new deal.
But the player has stood firm over his desire to ply his trade elsewhere next season.