Deputy Attorney General Rod Rosenstein, who appointed Special Counsel Robert Mueller to lead a probe into Russia’s interference in the 2016 U.S. presidential election and possible coordination with the Trump campaign, has signaled he would be leaving his post once the Mueller investigation is wrapped up and has run its course in the courts.

Recent rumblings have indicated that Mueller would file a report some time within the next two months, although the special counsel plays his cards close to the vest and recently asked for a six-month extension to his federal grand jury in Washington.

News of Rosenstein’s departure and what that might mean for the investigation comes as the Senate prepares to hold confirmation hearings for William Barr, President Trump’s pick for Attorney General. The nomination of Barr, who has already had a stint leading the Justice Department under President George H.W. Bush, has prompted concerns over his belief in broad executive powers and his criticism of the Mueller probe. But as he made the rounds recently on Capitol Hill, Barr apparently assured senators that he respected Mueller, his former deputy attorney general at the Justice Department, and would let the special counsel finish his probe.

“I asked Mr. Barr directly, ‘Do you think Bob, Mr. Mueller’s, on a witch hunt?’ He said no. ‘Do you think he would be fair to the president and the country as a whole?’ He said yes,” Senate Judiciary Chairman Lindsey Graham, R-S.C., told reporters.

He also promised to reviewing the Mueller report and deciding what could be shared, “erring on the side of transparency,” Graham said.