Michael Lorenzen's 7.03 ERA is the most volatile number on the board — but a Rockies lineup stripped of Moniak and Doyle keeps the ceiling low enough to complicate the over case. The under is sitting at +100, flat money on a total propped up by pitching instability rather than offensive firepower, and the gap between those two forces is where the real friction lives.
Colorado Rockies vs. Arizona Diamondbacks MLB Betting Preview
The first question any sharp bettor asks about this game is whether Arizona's -174 moneyline is playable. The answer is no — that price hard-fails a juice ceiling of -130, and there's no override for it. So if you believe the Diamondbacks are the right side, you need a different expression. The run line? Arizona Diamondbacks -1.5 at +115 is worth a glance, but one-run game risk is real given the last two games in this series went 3-2 and 2-1 — the -1.5 requires a win by two or more, and that's a margin I'm not comfortable mandating here. That pivots the betting conversation entirely toward the total, where the market is sitting at 9 with the under priced at +100 — even money. The numbers project to roughly 9.5 combined runs, which is a marginal gap, but even money on an under that barely edges over that figure is a price point worth serious attention.
Game Information & Betting Odds
- Matchup: Colorado Rockies @ Arizona Diamondbacks
- Date/Time: Saturday, May 23, 2026 — 10:10 PM ET
- Location: Chase Field, Phoenix, AZ (Dome)
- TV: MLB.TV, DBACKS.TV, Rockies.TV
- Moneyline: Colorado Rockies +146 / Arizona Diamondbacks -174
- Run Line: Arizona Diamondbacks -1.5 (+115) / Colorado Rockies +1.5 (-138)
- Total: 9 (Over -122 / Under +100)
- Probable Starters: Michael Lorenzen (COL) vs. Zac Gallen (ARI)
- Records: Colorado Rockies 20-32 (NL West) | Arizona Diamondbacks 26-24 (NL West)
The Pitching Matchup
The pitching matchup tilts this toward the under more on game-flow logic than starter dominance. Neither of these arms is inspiring confidence — this is about ceiling suppression, not shutdown performances.
Michael Lorenzen is genuinely one of the worst starting pitching profiles in baseball right now: 7.03 ERA, 1.91 WHIP, -0.97 WAR through 48.2 innings. His four-seam fastball — used on 30.9% of pitches — sits at just 89.9 mph and generates only a 19.5% whiff rate, which is below-average for a pitch he leans on heavily. The more damaging number is his sinker: 19.7% usage, a .412 xwOBA against — hitters are punishing that pitch when they get to it. His changeup (30.3% whiff rate) is his best swing-and-miss offering, but it's generating only a 5.9% put-away rate, meaning he's getting whiffs but not finishing batters.
Here's the problem, though: Arizona's lineup (.708 OPS) is not an elite offense. Ketel Marte leads the order with an xwOBA of .406 and has gone 5-for-11 in limited BvP looks against right-handed arms — he's the clearest run-creation threat in this lineup. Corbin Carroll is sitting at a .446 xwOBA with an 8.4% barrel rate and 31.8% hard-hit rate, but he's batting just .100 in 12 BvP plate appearances against Lorenzen. The ceiling exists, but it's not guaranteed to blow the roof off.
Zac Gallen is not a shutdown arm this season either — his 4.78 ERA and 1.43 WHIP reflect a pitcher who has been hittable. He leans heavily on a 96.2 mph four-seamer at 58.6% usage, which is holding opponents to a .355 xwOBA — not dominant. His slider is the better weapon: 18.4% usage, 30.3% whiff rate, .314 xwOBA against, 27.1% put-away rate. That's a genuine swing-and-miss offering. His curveball (.282 xwOBA against) is his best contact-suppression pitch, though it's only deployed 10.6% of the time. Colorado's lineup is already depleted — Mickey Moniak (IL, ankle) and Brenton Doyle (IL, oblique) are both out, removing two of the Rockies' better offensive pieces. The lineup Colorado is rolling out carries a team OPS of .692 against a starter who, despite his current ERA, still has quality secondary stuff.
From an efficiency standpoint on the mound, Gallen limits Colorado's upside. Hunter Goodman (.421 xwOBA, 27.9% hard-hit rate) is the most dangerous bat in the Colorado order, but he also carries a 31.1% strikeout rate — Gallen's slider should give him trouble. Troy Johnston (.417 xwOBA vs. RHP) bats fifth and is quietly one of the better contact hitters on this Colorado roster, but the middle-of-order punch is thin without Moniak.
Prediction
The game script here looks like a low-scoring, somewhat messy affair — Lorenzen will give up runs, but Arizona's offense isn't built to hang a crooked number on anyone consistently. The last two games in this series finished 3-2 and 2-1, and that recent scoring context isn't accidental. Chase Field plays as a slight pitcher's park at 0.97 run factor, which won't push the run environment up from neutral.
The concern is Lorenzen's volatility — a 7.03 ERA means he can absolutely implode and put this total in jeopardy by the fourth inning on his own. And with combined run expectation sitting around 9.5, this isn't a slam-dunk number. Both bullpens have injury attrition (Colorado missing Victor Vodnik and Jimmy Herget; Arizona with Jeff Brigham day-to-day), which adds genuine uncertainty to the late-inning run prevention picture. This is a lean, not a strong play.
That said, even money on the under is the right price for a number that's being propped up by a volatile starter rather than legitimate offensive firepower on either side. Gallen keeps Colorado's bats in check, Arizona's lineup is good but not great against a pitcher they've been unable to punish consistently in this series, and the park isn't adding anything. I'll take the under at +100 for one unit.
Bet: Under 9 (-100) — 1 unit