Andrew McCabe's decision to step down as FBI deputy director is reportedly tied to a forthcoming watchdog report on how the agency handled the investigation in Hillary Clinton’s private email server.

FBI Director Christopher Wray alluded in a message to all agency employees Monday night that he has seen information within the inspector general’s report, and tied that information to his accepting McCabe submitting his intention to retire.

"It would be inappropriate for me to comment on specific aspects of the IG's review right now," Wray said in the message obtained by NBC News. "But I can assure you that I remain staunchly committed to doing this job, in every respect, 'by the book.' I will not be swayed by political or other pressure in my decision making."

Wray and McCabe reportedly also met and discussed the IG’s probe.

McCabe, who was appointed by former FBI Director James Comey in January 2016, announced his intent Monday to go on “terminal leave” until he could retire and be eligible for full pension in mid-March.

The IG is investigating how the FBI handling the Clinton probe, and that report’s release is pending.

McCabe drew the ire of both President Trump and Republican lawmakers for being biased because his wife took donations from a Clinton ally while running as a Democrat for a Virginia state Senate seat — though the FBI released internal documents showing there was no conflict of interest for McCabe.

To the FBI, McCabe wrote Monday: "It is has been my privilege and honor to work with you all for the past 21 years. Please always remember that the key to those successes is an unflagging focus on integrity. You are the greatest workforce on earth because you speak up, you tell the truth and you do the right thing.”

It was reported last week that Wray was so protective of McCabe that he threatened to resign rather than give into pressure and oust his deputy director.