Arizona Diamondbacks starting pitching prospect Cristian Mena threw five shutout innings on Wednesday and tied a season-high nine punchouts. Through 50 innings with Triple-A Reno, Mena has a 3.42 ERA, 1.38 WHIP and 54:25 K:BB ratio. The 21-year-old got a small taste of Triple-A ball last season but struggled with a 5.95 ERA across 19 innings. While Mena is showcasing his elite strikeout upside, he is still struggling with his control. Mena should be expected to reach the major leagues later this summer and could become a must-stash player if he lowers his walk rate over his next few starts.