In August, in a separate trial in Virginia, a federal jury found Manafort guilty on eight counts of federal tax and banking crimes.
Such filings typically indicate that a deal has been reached.
The president has signalled that he's sympathetic to Manafort's cause, and in comments to Politico, his attorney-spokesman Rudy Giuliani said a plea without a cooperation agreement wouldn't foreclose the possibility of a pardon.
As part of his guilty plea agreement with special prosecutor Robert Mueller the former Trump campaign chairman will forfeit four of his homes: three in NY - including one in the Hamptons - and one in Virginia.
As much evidence as Mueller's team had against Manafort in the first trial, they have even more evidence in the second trial.
This, in turn, may endear him to President Trump, who has already called Manafort a "good man" who has been unfairly targeted by the Justice Department. But Trump's presidential pardon powers only exist at the federal level, and if Manafort were to be convicted in any possible state-level prosecutions, the president couldn't grant a pardon.
On Thursday, ABC News reported that Manafort's legal team had reached a tentative deal with Mueller's team after an hours-long meeting at the special counsel's downtown Washington, DC, offices.
The punishment that Manafort may receive related to his D.C. case, and any cooperation he may have offered the government, weren't immediately clear. "MANAFORT generated more than 60 million dollars in income as a result of his Ukraine work".
He said that, should the deal include Manafort's cooperation with Mr Mueller's Trump-Russia investigation, it could be bad news for the USA president.
At the time of Mr Gates' plea, Manafort issued a statement saying he "had hoped and expected my business colleague would have had the strength to continue the battle to prove our innocence".
That posture drew plaudits from Trump, who praised his former campaign chairman for his unwillingness to cooperate with the special counsel.
Writing on Twitter on August 22, Mr. Trump said, "Unlike Michael Cohen, he refused to "break" - make up stories in order to get a 'deal.' Such respect for a fearless man!"