Wacha will start Thursday's series opener at Cincinnati, Anne Rogers of MLB.com reports.
Manager Mike Schildt indicated over the weekend that Wacha was likely to start versus the Reds, so his return to the starting rotation isn't much of a surprise. The 28-year-old has a 5.54 ERA, 1.65 WHIP and 72:42 K:BB over 89.1 innings this season.