More than Deputy Attorney General Rod Rosenstein’s job will be on the line when he meets with President Donald Trump at the White House on Thursday. Also in the balance will be the fate of special counsel Robert Mueller’s Russia probe.

The ouster of Rosenstein — who serves as Mueller’s direct supervisor — would subject the special counsel’s probe to new uncertainty and, critics fear, new restrictions on Mueller’s investigation into ties between Russia and the 2016 Trump campaign.

Because Attorney General Jeff Sessions has recused himself from the Russia investigation, it is his deputy who approves everything from Mueller’s budgets to his subpoenas and the scope of his probe. And if Mueller produces a written report about his work, he will file it to Rosenstein or his successor, who will then decide what action to take in making the much-anticipated document public.