In particular, the list includes Health Department Secretary Alex Azar, Transportation General Counsel Steven Bradbury, former Attorney General Bill Barr, Deputy Secretary of State John Sullivan and retired appeals court judge Janice Rogers Brown, the Wall Street Journal reported Thursday citing unnamed White House officials and outside advisers.
Trump has been critical of Sessions ever since the Attorney General recused himself from the Russia probe. During an interview in August Trump slammed Sessions for the recusal and said the department was out of control.
Sessions responded in a letter saying the Justice Department will not be improperly influenced by political considerations.
Mueller is investigating allegations of Russian interference in the 2016 election, as well as any connections between Moscow and the Trump campaign. Russia has repeatedly denied allegations of interference, and both Trump and the Kremlin have firmly rejected accusations of collusion.
In September, Trump told Bloomberg Jeff Sessions was safe in his job until November but declined to say if he would keep Sessions in the role beyond then.