When appeared in court Wednesday, he pleaded not guilty to , but that plea is expected to be amended next month.
When he returns to court Oct. 25, officials from the U.S. Attorney's Office say they expect Cook will change his plea.
"The lawyers asked the judge to set the case for a change of plea," Randall Samborn, spokesman for the Chicago U.S. Attorney's office, said in a phone interview Wednesday afternoon. "A change of plea does not mean a defendant is bound to enter a guilty plea."
Samborn declined to speculate on why a defendant would make a choice to enter one plea and set a date to enter a different plea.
Cook faces stemming from charges of not filing federal income taxes between 2005 and 2008.
After the Tuesday night, Cook said he has been advised by his attorney not to comment on the case.