Harrington has thrown five-plus innings in eight straight starts for Double-A Altoona, logging a 2.80 ERA, 1.13 WHIP and 47 strikeouts in 45 innings over that span.
Harrington's season numbers are even better, but he wasn't pitching as deep into games early in the season. The 23-year-old righty matched a career high with 11 strikeouts in his most recent start July 10 against Bowie. He has three above-average-or-better offerings (fastball, changeup, slider) and also throws a cutter and a curveball. His 3.5-percent walk rate is the fourth-best mark among Double-A pitchers who have thrown at least 50 innings.