The drastic decline in Danny Duffy‘s performance, combined with exceeding his previous high of 149.2 innings pitched, suggest he might be fighting fatigue.
Duffy has pitched 173.1 innings with one more scheduled start in the season on Thursday (today). His average fastball velocity has dropped to a season-low 94.59 mph in September, down from 94.86 mph in his outstanding August and 95.13 in July.
A pitcher losing a little zip on his fastball in September is nothing unusual. In fact, most pitchers lose some velocity at the end of the season. However, Duffy’s walk rate also jumped to 2.