Harrison, 34, was cut by the Steelers on March 9 after he refused to take a pay cut. The five-time Pro Bowl player was scheduled to make $6.57 million in 2013.
Harrison has received very little interest in free agency, and he was taking a free-agent visit in Baltimore on Sunday when the Ravens agreed to terms with Elvis Dumervil.
Harrison's agent told ESPN NFL Insider Adam Schefter that he hasn't closed the door on his client returning to Pittsburgh.
The leading candidate to replace Harrison is Jason Worilds, a 2009 second-round pick.
“I believe that Jason Worilds is chomping at the bit to prove he is capable of being that," Steelers coach Mike Tomlin said last week at the NFL owners meetings.