The Dutchman, back in management after a mixed stay with Manchester United, replaced Real Madrid manager Xabi Alonso over the summer, but he has just one win to his name so far, that coming in the DFB Pokal against lower league opposition.
A sudden meeting between the two parties was called on Sunday, with the club, according to Sky Sport DE, criticising Ten Hag for lacking a clear game plan and insufficient structure, and communication with the team is also said to be lacking.
With an international break around the corner, it has not been ruled out that the 2023/24 league champions could make a snap managerial change.
In his two Bundesliga matchdays as Leverkusen boss, he lost the opener to Hoffenheim 2-1, whilst they let slip a 3-1 lead in a draw against Werder Bremen on Saturday, despite having a man advantage.
Ten Hag has a contract that runs until the summer of 2027, and reports suggest that he has the belief that he can turn it around.