Daniel Levin testifies before the House Judiciary Committee on June 18, 2008 in Washington.
PHOTO: Chip Somodevilla/Getty Images
Daniel Levin testifies before the House Judiciary Committee on June 18, 2008 in Washington.
(CNN) —  

The former chief of staff to Special Counsel Robert Mueller is in talks to possibly join President Donald Trump’s legal team, according to two people briefed on the discussions.

Daniel Levin – who once subjected himself to waterboarding so he could understand the interrogation technique in his legal analysis at the Justice Department – is in discussions to possibly join a team that includes Marc Kasowitz, the two sources said. The talks are ongoing and, given sensitivities in Washington legal circles over long-term blowback from clients who oppose the President, it’s not clear the two sides will reach agreement.

If he decides to join, Levin could end up squaring off against his former boss and friend. He formerly worked as chief of staff to Robert Mueller during Mueller’s tenure as FBI director. Mueller is now the special counsel who is building his own legal team to complete a yearlong investigation into Russian meddling in the 2016 election. Mueller has not opened a formal investigation into the President himself.

“He’s the first person in and the last person out, that’s the reason everyone claims he is the gold standard,” Levin told CNN about Mueller in May. Levin said his former boss brings a terrific judgment when it comes to the criminal justice system and a “very good sense of how things work.”

Levin added that Mueller’s most important quality is that he “has no ego.”

“He’s really not looking to make himself good. He will get to the right result, whatever it is,” he said in the May interview.

Levin, a partner in Washington at the White & Case law firm, declined to comment to CNN when reached on Tuesday, except to say “gee, thanks” when told that some in Washington are comparing his waterboarding experience with the work of representing a presidential client who is known to override the advice of his lawyers.

A spokesman for the President’s legal team didn’t comment.

Politico earlier reported on the discussions with Levin.

Levin left Mueller in 2002 and eventually took senior legal posts at the Justice Department and at the White House. It was during his time at the Justice Department when he became concerned about the interrogation techniques as some in the administration tried to fix what officials had come to believe were legal errors in their authorization.

Levin went to a military base and experienced the drowning sensation of waterboarding and later issued a legal memo that introduced tighter restrictions on any use of what the Bush administration called “enhanced interrogation” techniques.