There is a LOOGY and his name is Layne.
I don't see any reason to think Owens is a bullpen candidate. If he's not in the major league rotation--and if the others are healthy, I don't see why he would be--then he's in AAA waiting for someone to get hurt or suck.
Wright, Layne, and Escobar are out of options so if they decide to go with a long man, I think Wright and Lane are pretty close to locks. Escobar will likely make it through the waiver wire. That leaves us looking for a primary lefty and Ross is it. Maybe they don't go with a long man, in which case Elias, Hembree, Marmol and the like have a shot, but Wright is out of options, and he's been fairly effective in the bigs so he's got a good shot at the job regardless.
There just aren't really any interesting roster battles. If everyone is healthy, we can state with a pretty high degree of confidence who the rotation will be, who the bullpen will be, who the everyday lineup will be, and who the bench will be. It's not guaranteed, someone is probably going to get hurt, and there's a little wiggle room, but it looks like a pretty boring spring in terms of roster battles.