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Colorado Rockies vs Arizona Diamondbacks Starting Lineup — Wednesday, Aug 12, 2026

Wednesday, Aug 12, 2026Chase Field3:40 PMPreviewStarting Lineups
COL · Away

Colorado Rockies

SP: Ryan Feltner · ERA 5.71
@
3:40 PM
AZ · Home

Arizona Diamondbacks

SP: Merrill Kelly · ERA 4.88
Lineups PendingAnnounced ~1–2 hrs before first pitch · 3:40 PM ET
Full matchup preview

Expected Batting Order

Official lineups not yet announced for this game. Check back closer to game time.

No lineup data available for Colorado Rockies.

No lineup data available for Arizona Diamondbacks.

◆ Matchup preview

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.

Key facts
Rockies team ERA 5.48 and WHIP 1.51Feltner has allowed 1.98 HR/9Diamondbacks team ERA 4.10 and WHIP 1.29