The 28-year-old has been a key player for Leipzig since joining from Wolfsburg in the summer of 2022, making 97 appearances across all competitions.
Schlager’s contract at the Red Bull Arena is set to expire at the end of the season, and the club have now confirmed the player’s decision to leave.
"My last three-and-a-half years at the club have been marked by several unforgettable moments, in particular our DFB-Pokal and DFL-Supercup triumphs in 2023,” Schlager said in the announcement.
”I feel very at home here, both at the club and within the team. That's why I really appreciate the efforts the club and its management team have put into our discussions.
“Ultimately, what won out for me is my desire to experience and try something new. It wasn't a rejection of RB Leipzig, but rather a decision to pursue something new.
“Anyone who knows me will know that I will give my all for this club, our fans and our shared goals until the final whistle of my last game. My priority is to close this chapter of my life at RB Leipzig in a positive way!"