Among them will be Chicago Mayor Rahm Emanuel. Sources close to the case say that Emanuel is one of several high-profile witnesses the defense has been talking about calling and expect him to take the stand sometime Wednesday.
In 2008, Emanuel served as President Barack Obama's chief of staff and was corresponding with then-governor Blagojevich about possible replacements for Obama's Senate seat. Blagojevich is on trial in part for allegedly trying to sell or trade the seat to the highest bidder.
Congressman Jesse Jackson Jr. is also expected to appear on the witness stand to testify about allegations that Blagojevich considered a campaign cash offer in exchange for appointing him to the Senate seat. Neither Emanuel nor Jackson is accused of any wrongdoing.
Emanuel has been under subpoena to testify since Blagojevich's first trial last year.
"I'm ready, if asked, to answer questions, as I was in the first trial. And this trial, I will answer questions if I have to," Emanuel said.
Emanuel's office said Tuesday that he was notified that he may be called as a witness. It is still unclear whether Blagojevich will be taking the stand in his own defense.