Before the report's release, Trump had feared a repeat - but bigger - of the February testimony of his former lawyer and fixer, Michael Cohen, which dominated news coverage and even overshadowed his nuclear summit with North Korean leader Kim Jong Un in Vietnam.
The document asserts that Mueller found clear evidence that Russian Federation meddled in the 2016 presidential election to help President Trump and that some Trump campaign staffers welcomed the foreign assistance.
Zebley will be there to advise Mueller, but the special counsel will be the only one answering the committee questions, the source said.
The president has spent months concerned about the prospect of the media coverage that would be given to Mueller, who Trump believes has been unfairly lionized across cable news and the front pages of the nation's leading newspapers for two years, according to three White House officials and Republicans close to the White House.
Some Democrats in Congress support impeaching Trump, but they have not managed to win traction from House Democratic leadership including Speaker Nancy Pelosi, who has preferred a more cautious approach that entails conducting congressional fact-finding investigations into Trump's conduct.
Mr Mueller's appearance comes more than two years since the start of the Russian Federation investigation, an extraordinary moment in the Trump presidency when, after Mr Trump had fired FBI Director James Comey, his Justice Department appointed Mr Mueller to take over the inquiry into election interference and the potential role that Mr Trump and his winning 2016 campaign may have played.
Palace shares heartwarming new pictures to celebrate Prince George’s birthday
And it's clear that George is developing his own personality from the candid snaps taken by his mother, Kate Middleton . Prince George now attends London's Thomas's Battersea, and come this autumn, little sister Charlotte will join him.
"If you look at him and his career, he is someone who comes to the table fully prepared and he's going to be ready on Wednesday", he said.
Mueller, an ex-Marine with a famously taciturn style, never relished his congressional appearances in his 12 years as Federal Bureau of Investigation director - and this will be no exception. "And the report is my testimony". Expect Republicans to invite him to relate that story early and often - and to press him about why they should accept anything from an office that included Strzok and others who've been criticized for political "bias". "The President raised his previous request and asked if Lewandowski had talked to Sessions", the report says. Consistent with standard practice, Department witnesses should decline to address potentially privileged matters, thus affording the Department the full importunity at a later date to consider particular questions and possible accommodations that may fulfill the committees' legitimate need for information while protecting Executive Branch confidentiality interests.
Mueller has made clear he didn't think it was appropriate to make a determination one way or the other about whether the president had committed a crime. But the report was vague on obstruction. The goal, they said, is to create a made-for-television production to drive the report home to Americans.
Mueller probably doesn't want to extend a public war of words with Barr, a longtime friend and his former boss.
But that doesn't mean they won't have areas to mine.
"The narrative we must tell is that we are American", he said. "We have to expose his biased investigation". Alexandria Ocasio-Cortez (N.Y.), Ilhan Omar (Minn.) and Ayanna Pressley (Mass.) - beginning with a racist tweet saying they should "go back" to the countries they were from originally.