Mayorga doesn't care. He's in the ring because there's a lot of money at stake. He was threatening to retire after the Forrest fights. If he really cared about winning fights he'd still be at 147. He hasn't had a convincing performance since then.
I'm going with Vargas. Unless he's totally shot (which he may be), I don't think it will be difficult to look good against Mayorga. I'm a huge fan of Ricardo's, but the writing has been on the wall for a long time.
I don't think Mayorga has enough sense to be worried. This is what will most likely help him in this fight against Vargas. He has a chance, maybe a punchers chance to ko a very beatable Vargas, who was never much to begin with.