Gerald Lefcourt, another defense lawyer in New York, said, "The obvious strategy is to blame Gates for everything and argue his credibility which clearly took a big hit on cross."
"If Manafort testifies he shifts the jury's attention from Gates' credibility to his own credibility," Lefcourt said. "That's a real problem, because the person who's got the most to gain by fabricating is the defendant."
Brennan agreed with that, saying that Manafort risked a lot by taking the witness stand, even if he thought he would be able to sway the jury to believe his version of events.
Brennan noted that federal prosecutors have access to files about a defendant from a raft of government agencies, including the FBI, IRS and Securities and Exchange Commission, all of which can be used to undercut that defendant's testimony during cross-examination.
As a result, he said, for most criminal defendants in federal trials "it's a losing game" to take the witness stand "unless you have a really good story to tell."
Manafort's legal team, however, is leaving unrebutted by any witnesses the stack of financial documents entered into evidence by prosecutors against Manafort.
Prosecutors argue those records are damning evidence of Manafort hiding money earned overseas from consulting for a pro-Russia political party in Ukraine and then duping banks into giving him loans when that income stream ran dry.
For Manafort's lawyers, "The risk is that you don't have any answers to the statements that the prosecutors are going to make" in closing arguments, Brennan said.
But "the defense strategy is to ignore the documents" and "be focused on Gates" in closing arguments to jurors, Brennan said.
"I'd stand up there in front of them and say, 'Why does Manafort even have to be here?'" Brennan said.