In a characteristically unorthodox move, President Donald Trump is reportedly poised to tap New York commercial litigator Marc Kasowitz, an associate of former Sen. Joseph Lieberman, to lead his personal legal team amid probes into his campaign's alleged contacts with Russia.

The choice appears to diminish Lieberman's chances of becoming the nation's next FBI director, less than a week after the White House announced he was on the short list to replace fired former director James Comey. The former Connecticut senator is a senior member of Kasowitz's firm, Kasowitz Benson Torres, which brought billions of dollars in claims against Wall Street banks in the wake of the subprime crisis.

Far from an established, Washington, D.C., white-collar figure, Kasowitz is best known for handling a mix of complex, high-stakes civil disputes in New York's state courts, particularly involving financial institutions. He has also been a loyal attorney for Trump and his interests for close to two decades, in matters ranging from defamation to debt restructuring for Atlantic City casinos. Former Kasowitz Benson named partner David Friedman, a bankruptcy lawyer who was appointed U.S. ambassador to Israel this year, was also a longtime Trump adviser.

Before Fox Business News and ABC News first reported Trump's selection of Kasowitz on Tuesday evening, citing unnamed sources, The Washington Post had identified him as one of four lawyers under consideration for the job. The others were Robert Giuffra of Sullivan & Cromwell (a fierce adversary of Kasowitz in financial crisis litigation); appellate lawyer Theodore Olson of Gibson, Dunn & Crutcher; and Washington criminal defense lawyer Reid Weingarten of Steptoe & Johnson LLP.

It's not clear whether some of those attorneys or others could join a team of outside Trump lawyers under Kasowitz's direction. A larger team would appear necessary, however, especially given Kasowitz's relative lack of experience with white-collar matters and political investigations. As the president's outside lawyer, Kasowitz would have a separate mandate and responsibilities from White House Counsel Donald McGahn II.