Chafin walked the lone batter he faced on five pitches during Wednesday's 5-4 loss to the Rockies.
Chafin has been the Diamondbacks' top choice for lefty-on-lefty matchups for the bulk of the season, but his recent struggles may have resulted in Jake Diekman surpassing him in the bullpen hierarchy. The 28-year-old has walked five of the past seven batters he has faced, eliminating any utility he offers in his situational role. Manager Torey Lovullo may want Chafin to iron out his control problems in lower-leverage spots before turning to him again late in close games.