Perez is the "safe" choice if there is one in the bunch, but I think I'd opt for Balfour. To be honest I don't think he's even 2nd in line to Percival for save ops. I'd guess by the contract for "closer money" that Wheeler received he'd get the first opportunity, but given his previous struggles in the closer spot, I think he's better suited for 8th inning duty, which means Balfour would probably ultimately end up in the gig. Gotta love his ratios last year (though I'd expect regression this year... still if it's only mild his ratios would be fantastic) and his K rate was fanstic. The question with Balfour even going back to his Brewers days was not whether he had the stuff, but if he could find the strike zone. If you want to take the safer selection with some upside go Perez, if you feel like rolling the dice a little bit for a guy who's immediate ceiling I think is higher (but who's floor is lower) go Balfour. Either way, I'd avoid all others not named Perez or Balfour. Good luck!