Ravens defensive end Arthur Jones won't be on the field Thursday when Baltimore kicks off the NFL season against the Broncos. And very few people seem to know exactly why.

Ravens coach John Harbaugh only has said that the illness Jones is battling is not life-threatening and that the team doesn't know how long he'll be out. And Jones has said nothing other than this.

OK so what's going on here?

"I'd rather leave an explanation of Art's situation up to Art" Harbaugh said Wednesday via the Baltimore Sun. "It's not anything that's like life-threatening or anything like that. It's non-football related. We've got to get some tests done to make sure that he's OK. Until the tests come out the right way he's not going to be able to play.