According to John Fay:

GOODYEAR, Ariz. — The minor leaguers reported to camp today. Among them was Mark Prior.

Yes, that Mark Prior.

Prior, a 32-year-old right-hander, has not pitched in the majors since 2006 because of shoulder problems. He’s made several comeback attempts since.

“He called me and said asked for a chance,” Reds manager Dusty Baker said. “I talked to Walt (Jocketty). (Prior) says he feels good. He feels like he has some unfinished business.
http://cincinnati.com/blogs/reds/201...with-the-reds/