Donald Trump took a premature victory lap Monday morning after news broke that his former campaign manager, Paul Manafort, and another former staffer, Rick Gates, had been indicted on 12 counts that were seemingly unrelated to the collusion question that has hung over Robert Mueller’s sprawling investigation. He lapsed into silence, however, when it emerged that a third former staffer, George Papadopoulos, had pleaded guilty to lying to the F.B.I.—revelations that immediately raised the stakes for the Trump administration and revealed that Mueller’s probe is clearly focused on the collusion question.

In March 2016, Trump had given Papadopoulos a shout-out during a presser, calling him “an energy and oil consultant, excellent guy.” (Days later, according to the Justice Department, Papadopoulos would present the campaign with a proposal to coordinate with Russia to get compromising information about Hillary Clinton.)

On Tuesday morning, however, Papadopoulos found his former status suddenly downgraded. “Few people knew the young, low level volunteer named George,” Trump tweeted, after reportedly “seething” over the indictments. Papadopoulos, he said, “has already proven to be a liar.”

His wording echoed what White House press secretary Sarah Huckabee Sanders repeatedly said at Monday’s press briefing: that Papadopoulos was “a member of a volunteer advisory council that met one time over the course of a year” who had “little role . . . [in] coordinating anything officially for the campaign.”

Papadopoulos is one in a long line of aides the Trump campaign has tried to dismiss as irrelevant. Earlier this year, Sean Spicer said that Manafort “played a very limited role [in the campaign] for a very limited amount of time,” and Sanders stuck to that messaging on Monday. But the administration’s attempt to discredit “George” rang equally hollow. As Chris Smith wrote for Vanity Fair on Monday, Papadopoulos’s role in the campaign was not insignificant—he was an energy adviser photographed sitting between Trump and his eventual attorney general, Jeff Sessions—and according to the plea document, Papadopoulos had been actively back-channeling Russian entreaties and intel to the campaign’s senior-level advisers, including the revelation that they were in possession of stolen e-mails from the Democrats and Clinton.

One former Trump adviser, Michael Caputo, responded to the news by calling Papadopoulos a “coffee boy” who “had nothing to do with the campaign.” Mueller apparently didn’t think so: according to court documents, he spent months as a cooperating witness, and may have even worn a wire.

This article has been updated.