Washington (CNN) White House counsel Don McGahn's 30 hours of conversations with special counsel Robert Mueller's team have unnerved President Donald Trump, who didn't know the full extent of McGahn's discussions , two people familiar with his thinking said.

The meetings only add complications to the already-fraught relationship between the President and the White House's top lawyer. And as nervous aides await a verdict in former Trump campaign chairman Paul Manafort's trial and watch with trepidation the inauspicious public relations blitz carried by lead attorney Rudy Giuliani, uncertainty surrounding the President's handling of the Russia investigation abounds.

Trump was spending another weekend at his New Jersey golf club when The New York Times first reported McGahn's cooperation with Mueller's office, which is investigating Russian attempts to interfere in the 2016 election.

The President was unsettled by the notion that he didn't know everything McGahn said to the special counsel during their interviews, the sources said. And while he had approved the cooperation, Trump did not know the conversations stretched for 30 hours or that his legal team didn't conduct a full debriefing with McGahn after the fact.

Trump remained agitated for the rest of the weekend, the people said, believing the revelation made him look weak. Between conversations with his lawyers and a round of golf with Sen. Rand Paul, Trump lashed out on Twitter, decrying the suggestion he was caught off guard.

"I allowed him and all others to testify - I didn't have to. I have nothing to hide and have demanded transparency so that this Rigged and Disgusting Witch Hunt can come to a close," Trump wrote.

As his aides worked to react to the story, Trump insisted on portraying his relationship with McGahn -- one of his longest-serving aides with whom he's nonetheless clashed -- as ironclad.

"The President and Don have a great relationship," press secretary Sarah Sanders said on Saturday. "He appreciates all the hard work he's done, particularly his help and expertise with judges."

A White House official said Trump himself dictated the statement -- not an uncommon practice for the media-focused President, yet still an indication of his focus on the matter.

McGahn was on Capitol Hill Monday escorting Supreme Court nominee Brett Kavanaugh to meetings when he was peppered with questions from reporters about his conversations with Mueller's team. The lawyer, dressed in a navy suit and bright blue tie, maintained a stony exterior and didn't answer, proceeding along with the nominee who could come to shape Trump's judicial legacy. It's the issue upon which McGahn has focused most intently in his tenure.

A tortured partnership brings some of Trump's biggest victories

His declaration of a "great relationship" aside, Trump and McGahn have carried out a tortured partnership for more than a year, people familiar with the dynamic say.

According to officials, Trump has at times seemed unclear on McGahn's role -- which is not as his personal lawyer, but as a lawyer for the White House and the presidency.

McGahn enjoys rare status in the West Wing as an official who has openly defied the President— in one case last year, he refused to order the Justice Department to fire Mueller, despite Trump's command.

But it has come at a cost. Trump and McGahn -- once close partners who forged a bond when McGahn joined Trump's campaign in its early stages -- now rarely meet one-on-one, a source familiar with their relationship said. Instead, Trump and McGahn now often only meet as part of a broader meeting, often times one involving White House chief of staff John Kelly.

Inside the West Wing, speculation about McGahn's eventual departure from the staff was boiling for months before being cooled by the retirement of Justice Anthony Kennedy, which presented McGahn a second opportunity to help shape the Supreme Court.

It's in that realm that McGahn and the President have found themselves most aligned and successful. Trump has proudly trumpeted the conservative reshaping of the federal judiciary that McGahn has masterminded and executed from his wood-paneled office on the second floor of the West Wing.

Trump often raises the judicial effort during dinners and phone calls with his close advisers and friends, people familiar with the conversations say. At the same time, Trump has openly complained that he does not fully trust McGahn, and has wondered aloud if he was among those leaking damaging information about the White House.

For McGahn, too, the judicial effort has provided a reason to remain in the West Wing, even as his relationship with Trump deteriorated and the Russia probe drew closer to the President. Sources close to the White House said McGahn is likely to leave his White House post after Kavanaugh is confirmed.

What's McGahn's future?

Trump and McGahn went weeks without speaking at the beginning of this year, and months without meeting one-on-one, people familiar with the matter said. During this period, along with telling people McGahn was "a leaker," Trump complained about McGahn's good relationship with Deputy Attorney General Rod Rosenstein, who oversees the special counsel investigation.

This summer, Trump has stopped raising McGahn's relationship with Rosenstein as frequently, a person familiar with the matter said. The two men resumed one-on-one meetings around the latest Supreme Court nomination efforts, though one person familiar with the dynamic between them compared the duo to "old married couple complaining about each other."

McGahn -- who, as White House counsel, makes a fraction of the money he was making as a lawyer at Jones Day -- has long viewed his role as laying the groundwork for Trump's legacy-making moves. He's also had a hand in the administration's deregulation efforts, which are sweeping.

But, as White House counsel, he has not played a major role in directing the President's legal maneuvering when it comes to the Russia investigation. He was skeptical of the initial strategy, laid out by Trump's ex-lawyers Ty Cobb and John Dowd, of cooperating fully with Mueller's team. McGahn was a main internal advocate of bringing aboard Emmet Flood, who now directs the Russia legal strategy from inside the White House. Flood is viewed as a potential replacement for McGahn should he depart as White House counsel.

With details of McGahn's participation with the special counsel made public, experts say it's only a matter of time before other Trump aides seek out Mueller for interviews.

"Nobody wants to be the last one standing," said Jack Quinn, who served as White House counsel under President Bill Clinton and is now a CNN legal analyst. "Nobody wants to watch one's colleagues go in, spill the beans and be the one who is last in line to cooperate. I think there is a good chance you will see a lot of people making phone calls to the special counsel's office asking when their interview can take place."