South Carolina attorneys Butch Bowers and Deborah Barbier and former federal prosecutors Greg Harris, Johnny Gasser and Josh Howard had abandoned the defense group by Saturday, a source said, calling it a mutual conclusion.
The source said the attorneys left over a difference of opinion on the management of the defense's argument.
Another unidentified source told the Associated Press Bowers and Barbier left since Trump needed them to earn election fraud allegations throughout the trial.
New improvements were expected to join in the week beforehand.
The changes include minimal time before the president faces charges he incited the insurrection in the U.S. Capitol on Jan. 6, leaving the specific members of his defense team and their strategy up in the atmosphere in a vital moment.
Trump was certain to be acquitted, but since 45 from 50 Republicans in the Senate voted earlier this month to dismiss the trial on a point of order caused by Sen. Rand Paul, R-Ky.
The rest five Republicans voted to end discussion on Paul's movement that argued Trump's impeachment trial is unconstitutional because he is no longer in office.