Of those you mentioned, Lopez and Abel are coming back from injuries, and as of now I have no idea what to think of Joe Ryan. I actually do think Lopez will be fine, but depth is a good thing, and frankly you can never have enough pitching.
I also can't imagine Festa getting a chance to start again and being healthy enough for that. He, and to another extent Matthews, are bullpen arms for me next year. I'd love to be wrong.
But yeah, of those you mentioned, Lopez and Kremer should be good to go. Ryan probably. Bradley for sure. Actually Prielipp I would solidly add in there as of now, and I'd also be open to Rojas getting more leash. I don't know if Ober will be back for sure (maybe he is a trade candidate) but then I can easilly see the argument for spending on a durable starter in free agency too.