CHICAGO — A federal judge on Wednesday gave Rod Blagojevich's former chief of staff a light sentence of 10 days in prison for helping the imprisoned former Illinois governor attempt to sell President Barack Obama's vacated Senate seat.

John Harris' sentencing came two weeks after the former Illinois governor reported to a Colorado prison to begin serving a 14-year prison term on related charges. Harris pleaded guilty to conspiracy to commit bribery in a 2010 plea agreement. He faced up to five years.

Harris, 50, began cooperating just days after both men were arrested at their homes on Dec. 9, 2008. His cooperation included testifying against Blagojevich.

U.S. District Judge James Zagel praised Harris for his cooperation with investigators and said that he sympathized with Harris having to deal with such a difficult boss as Blagojevich. But while heaping praise on Harris, the judge said that some, but minimal, time in prison was necessary.

"The offense is so serious and so crucial that I cannot impose upon you a sentence that does not involve custody," Zagel said.

Zagel spoke at length about Blagojevich and his working habits and how he wore down his staff. Zagel even said that if he were in Harris' shoes he may have acted the same way.

"But I would have left sooner, much sooner," Zagel said.