(CNN) President Donald Trump, stung by reports that he couldn't attract top-notch lawyers, personally pushed for former New York City Mayor Rudy Giuliani to add a dose of star power to his bare-bones legal team, according to sources familiar with the situation.

In bringing on Giuliani, a former US attorney for the Southern District of New York, the President adds a high-profile name, trusted confidant and dogged defender in an investigation that Trump has denounced as a "witch hunt."

His hiring and that of two other new lawyers, respected white-collar criminal defense attorneys Jane Serene Raskin and Marty Raskin, injects some much-needed firepower into the President's legal team, which has been beset by departures and internal dissension and stalled in talks with special counsel Robert Mueller's team.

The President believes that Giuliani -- a brash New Yorker with a reputation as a tough prosecutor -- can assess Mueller's team and possibly shepherd a swift end to the investigation, according to a source familiar with Trump's thinking.

"Rudy is great," Trump said in a statement Thursday. "He has been my friend for a long time and wants to get this matter quickly resolved for the good of the country."

But not all involved with the legal defense are sanguine that Giuliani can succeed where others have failed. The notion that he will be able to quickly get a read on Mueller's team, said one source, is "not serious thinking."

Another source familiar with the case added that dealing with Mueller is "like going to talk to Abe Lincoln at the end of the mall -- a marble statue."

Changing team

The new hires round out a more legal robust team for Trump.

Lawyer John Dowd has previously taken the lead on talks with Mueller, but Dowd's abrupt departure threw things into disarray and left Jay Sekulow, Trump's outside counsel, to deal with Mueller's team while scrambling to beef up the President's legal defense.

Now Giuliani, the Raskins and Sekulow will serve as the President's outside counsel, while Ty Cobb will continue to serve as the White House special counsel. Attorney Joanna Hendon is representing Trump in the case involving Michael Cohen in the Southern District of New York.

White House Counsel Don McGahn has been mostly focused on issues that don't involve the Russia investigation. A witness himself in the Mueller probe, McGahn has met with Mueller's team on at least three occasions to answer questions, according to sources familiar with the matter.

At the outset of Giuliani's work for the President, he is expected to play a lead role in the interactions with the Mueller team.

"We're back on track and this should help bring this down the home stretch," said one source close to Trump.

But the President's team has expressed similar optimism in the past, only to be angered and disappointed when their expectations didn't pan out.

Until the FBI raid on the office, hotel and home of Cohen, Trump's longtime personal lawyer, Mueller's team and Trump's lawyers had been in discussions over whether the President would sit for an interview with the special counsel.

Discussions with Mueller's team have been in "limbo," since then, according to a source with knowledge. News of the raid blindsided Trump's lawyers, who considered the move a "major breach of trust" that shattered the assumptions of good faith going into the negotiations, one source previously told CNN. Another said it left the President's team feeling "fundamentally misled."

Mueller's team isn't likely to change its approach simply because of Giuliani's presence, a source said.

Still, Giuliani knows Mueller from prior work at the Justice Department as well as Mueller's tenure as FBI director while Giuliani was New York's mayor. Some Trump allies are hopeful that Giuliani will be able to elicit a different reaction -- if only because he'll approach the talks differently himself.

While Trump's legal team has already gone back and forth with Mueller's team about topics for an interview with the President, Giuliani may discourage Trump from testifying, a source said.

"He'll look at those 49 questions and say, 'What are you wasting my time for?'" the source said.

Giuliani told CNN in an interview that he intends to obtain a list of what is necessary to "comply" with the rest of the investigation from Mueller. He predicted that compliance could be completed in "a couple of weeks."

Giuliani's personal relationship with Trump, who has a habit of pinging longtime friends and advisers for counsel, was another bonus in adding him to the team, a source said. He and Giuliani are known to speak on the phone and hit the links together. When the two men spoke at Mar-a-Lago recently, Giuliani told the President he wanted the job, one of the sources said.

Giuliani also served as a loyal foot soldier in some of the darkest moments during Trump's presidential campaign.

In the aftermath of the "Access Hollywood" tape showing Trump bragging about groping women, then-Republican National Committee Chairman Reince Priebus and then-Trump Campaign Manager Kellyanne Conway both canceled their appearances on Sunday morning news shows. Giuliani, meanwhile, faithfully made the rounds on television defending Trump.

Yet Giuliani could also find himself embroiled in an offshoot investigation. In late October, during the presidential election, Giuliani went on Fox News to tease some "big surprises," saying, "We've got a couple things up our sleeve that should turn this around."

Two days later, then-FBI Director James Comey announced he was reopening the investigation into Clinton's emails.

In an interview with MSNBC on Thursday, Comey said he commissioned an investigation into leaks from the bureau's New York office after Giuliani's remarks and other leaks in the media.

"I don't know what the result of that was," Comey said. "I got fired before it was finished."

Giuliani has said in the past he had no insider information.

How the Raskins' expertise helps

While the Raskins did not have a prior relationship with Trump, they met with the President recently at Mar-a-Lago, two sources said. Trump was impressed with their expertise and approved their hiring.

"What you've got here are two very serious white-collar lawyers who know how to defend their clients," CNN legal analyst Michael Zeldin said of the Raskins. "That's what the President needs."

It's not clear where the Mueller investigation will ultimately lead, but the Raskins' experience in financial crimes could prove useful, Zeldin said. Mueller has already built out a team of lawyers with financial crimes expertise as part of his investigation into Russian meddling in 2016 and potential collusion with the Trump campaign.

The Raskins are expected to spend more time in Washington to interact with the Mueller team. Jane Raskin worked with Mueller at the Justice Department and at a law firm with James Quarles, one of the senior prosecutors on the Mueller team who is assigned to matters related to Trump, according to sources familiar with the workings of the Mueller team.

They could also serve as a moderating force to Giuliani's blunt style, Zeldin said.

"They're not limelight people," said Zeldin, who overlapped with Jane Serene Raskin when they both worked at the Justice Department. "They're team players."