The Brewers claimed righty reliever Roque Mercedes off waivers from the Diamondbacks, tweets MLB.com's Adam McCalvy. This gives the Brewers 37 players on the 40-man roster. Mercedes had been designated for assignment by Arizona on Friday along with Rusty Ryal's release to clear spots for Henry Blanco and Xavier Nady.
Mercedes, 24, came up through the Brewers' system and was traded to Arizona in July of last year in the Felipe Lopez deal. This year at Double-A he posted a 4.36 ERA, 7.5 K/9, 4.0 BB/9, and 0.8 HR/9 in 53 2/3 innings. Heading into the season, Baseball America ranked Mercedes 28th among D'Backs prospects, saying, "he could develop into a seventh-inning reliever."