Ajer is out of contract at Celtic Park next summer and is ready to move on from the club this summer as he seeks his next challenge in the game.
It has been claimed that both Leverkusen and Norwich have offered £10m for Ajer, which Celtic have rejected, leaving the player unhappy.
However, while Leverkusen are fighting for Ajer’s signature, they have not offered the amount that has been claimed, according to German daily Bild.
It is unclear how much Leverkusen have offered Celtic for Ajer.
Leverkusen did business with Celtic in January this year, raiding Celtic Park to snap up right-back Jeremie Frimpong.
The two clubs share a good relationship, but the jury is out on whether they will be able to reach an agreement for Ajer to make the move to the BayArena.
Ajer has made a total of 176 appearances across all competitions for Celtic since joining the club in 2016.
