Colorado Rockies vs Arizona Diamondbacks

Colorado Rockies at Arizona Diamondbacks (2026-08-12). Ryan Feltner vs Merrill Kelly at Chase Field.

Starters — Ryan Feltner has a 5.71 ERA and 1.45 WHIP across 82.0 innings, with 6.48 K/9, 3.62 BB/9, and 1.98 HR/9. In his last three starts, he allowed 3 earned runs in 5.1 innings with 2 strikeouts and 3 walks, then 4 earned runs in 6.0 innings with 3 strikeouts and 1 walk, then 5 earned runs in 5.0 innings with 4 strikeouts and 1 walk. The trend is down, and the home run rate remains a clear pressure point. Merrill Kelly has a 4.88 ERA and 1.47 WHIP over 120.0 innings, with 6.00 K/9, 3.75 BB/9, and 1.73 HR/9. In his last three starts, he gave up 1 earned run in 5.2 innings with 4 strikeouts and 4 walks, then 5 earned runs in 5.0 innings with 5 strikeouts and 4 walks, then 0 earned runs in 5.2 innings with 6 strikeouts and 1 walk. The trend is up, driven by two strong outings in his last three.

Teams — Colorado brings a .744 OPS, .255 average, and 571 runs scored, which is the better offensive profile in this matchup. The Rockies are 4-6 in their last 10 games, and their pitching staff has struggled to a 5.48 team ERA and 1.51 WHIP. Arizona has a .710 OPS, .242 average, and 548 runs scored. The Diamondbacks are 5-5 in their last 10, and their team pitching has been notably steadier with a 4.10 ERA and 1.29 WHIP. That creates a split matchup: Colorado has the stronger bats by the raw season numbers, while Arizona has the more reliable run prevention.