Mets vs Diamondbacks Predictions & Props to Bet (May 9)

• The underperforming New York Mets visit the Arizona Diamondbacks in the second game of their series
• Juan Soto could be in a great position to dominate the Diamondbacks in this matchup
• Keep reading to see the latest odds and our best predictions

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The New York Mets (14-23) and Arizona Diamondbacks (17-19) are continuing their series at Chase Field in Phoenix, Arizona, with the first pitch scheduled for May 9, 2026, at 7:15 PM ET. The Mets look to build on their momentum after securing a tight 3-1 victory over the Diamondbacks in their previous matchup. Mark Vientos propelled the offense with a crucial home run, overcoming an error-free defensive showing from the home team and a solo shot from Nolan Arenado.

With both clubs trying to gain ground in the early-season standings, the betting markets are keeping a close eye on this tilt. The visiting Mets enter as slight road favorites against the home underdog Diamondbacks. I will be zeroing in on elite talents like Corbin Carroll and Ketel Marte to see if they can spark a turnaround at the plate to back up their pitching staff.

Mets vs Diamondbacks Picks & Predictions

Moneyline Prediction: Mets Moneyline (-115 at Caesars Sportsbook)
The starting pitching discrepancy in this matchup makes it difficult to back the home side. Clay Holmes takes the mound for the Mets, entering this contest with an efficient 1.69 ERA and a 0.98 WHIP over 42.2 innings of work. The rotation has been steady as a whole, posting a combined 3.91 ERA. Conversely, the Diamondbacks are sending Merrill Kelly to the rubber, and he has struggled out of the gate. Across 19.0 innings, Kelly is laboring with a 9.95 ERA, an elevated 2.32 WHIP, and is surrendering 2.84 home runs per nine innings. With Holmes showing an ability to limit damage and Kelly struggling to keep runners off the basepaths, backing the Mets to win straight up is my primary moneyline play.

Over/Under Prediction: Over 9 Runs (-118 at DraftKings)
While the offense for the Mets has been quiet overall—averaging a .227 batting average and a .639 OPS—facing Kelly presents a favorable environment. Kelly’s tendency to give up the long ball sets up a strong situational angle for power hitters to generate extra-base hits. Meanwhile, the offense for the Diamondbacks has been the brighter spot for their club, compiling 162 runs and a .698 team OPS. Even though Holmes has been effective, the Diamondbacks have capable bats who can attempt to manufacture runs against a 3.93 ERA bullpen if they trail late. I expect a higher-scoring affair driven by the Mets capitalizing on early pitching struggles.

Top Player Prop: Juan Soto Over 1.5 Total Bases (-105 at BetMGM)
Given Kelly’s susceptibility to giving up hits (.358 opponent batting average) and home runs, targeting the top of the lineup offers solid betting value. Juan Soto has been a reliable force, boasting a .494 slugging percentage and an .868 OPS with four home runs on the season. Soto is averaging 1.04 hits per game and matches up well against a struggling pitcher. At -105 odds on DraftKings to record two or more total bases, Soto is positioned to take advantage of Kelly’s 2.32 WHIP.

Odds as of May 9, 2026, at 11:49 AM ET from BetMGM, Caesars Sportsbook, and DraftKings

Clay Holmes vs Merrill Kelly

The pitching data highlights two starters heading in opposite directions to open their 2026 campaigns.

Holmes has been highly dependable. Sporting a 4-2 record and a 1.69 ERA, he has held batters to a .184 average. While his strikeout numbers sit at 6.54 K/9, his command and ability to keep traffic off the bases allow him to pitch deep into games, averaging 6.10 innings per start. His 3.65 FIP suggests he has benefited from strong defense, but his ability to suppress home runs (0.63 HR/9 over his last 10 appearances) makes him a reliable arm.

On the other side, Kelly is searching for answers. The veteran right-hander holds a 1-3 record and a 9.95 ERA. He is currently issuing 7.11 walks per nine innings while allowing opponents to hit .358 against him. This translates to a 2.32 WHIP, restricting his length to just 4.75 innings per start. It’s always interesting to see the latest MLB batters vs pitchers stats.

Team Stats & Betting Trends

When handicapping this National League clash, looking at how the Mets perform on the road versus how the Diamondbacks play at Chase Field provides crucial context.

The most notable mismatch in the data is the production gap between the home and road offenses. The Diamondbacks are plating 4.63 runs per game in front of their home fans, ranking 13th in the majors. Conversely, the Mets have sputtered as visitors, managing 3.60 runs per game and struggling to get on base with a .650 OPS. Check the latest MLB starting pitchers and lineups before you place your bets.

However, diving into the contact metrics reveals an interesting paradox. The Mets boast an impressive 89.1 mph average exit velocity on the road, good for 7th in the league. The Diamondbacks sit below the league average at 87.9 mph. This hard-hit data perfectly aligns with my recommendation on Soto, suggesting the Mets are making solid contact but are hindered by a lack of sequencing or by failing to capitalize with runners in scoring position.

Team Betting Trends

• The Mets have failed to capitalize when favored by oddsmakers, holding a 36.0% win percentage (9-16) as the betting favorite.
• The Over has hit in just 34.2% of the Mets’ games this year.
• Despite season-long struggles, the Mets are 6-4 (60.0%) in their last 10 games.
• The Diamondbacks enter this matchup cold, having won just 20.0% of their last 10 games (2-8).
• Over their last 10 games, the Diamondbacks hold a 12.5% win rate when listed as the underdog (1-7).
• Across the entire season, the Diamondbacks have secured a 60.0% win percentage (6-4) as the favorite.

Mets vs Diamondbacks Odds & Public Betting

Odds as of May 9, 2026, at 11:52 AM ET from Bet365, Caesars Sportsbook, and DraftKings

MLB odds currently position the visiting Mets as slight road favorites on the moneyline at -115, while the Diamondbacks are listed at even money (-105). The game total originally opened at 8.5 runs but has since been bumped up to a flat 9.

The moneyline market is seeing increased support for the visiting side, according to the MLB public betting percentages. The Mets are currently commanding 75% of the betting tickets, backed by 84% of the total stake. While line movement and public money do not, on their own, equal value, this heavy market alignment mirrors my analysis of the pitching discrepancy between Holmes and Kelly.

The sentiment in the total market is nearly as decisive. Bettors are heavily anticipating run production, with the Over attracting 69% of the ticket count and 71% of the overall stake. The public and larger stakes are both attacking the Over, likely zeroing in on the 13th-ranked home offense to do damage, while relying on the visiting power hitters to capitalize on Kelly’s elevated home run rate.

Mets vs Diamondbacks Injury Report

Both clubs are battling significant attrition early in the 2026 campaign, which directly impacts positional depth and lineup construction.

The offensive struggles on the road for the Mets make mathematical sense when examining their crowded injured list. Managerial options are restricted with cornerstone players like Francisco Lindor, Luis Robert Jr, and Jorge Polanco sidelined. The lineup is top-heavy by necessity right now, explaining why betting on individual player props offers strong value.

On the other side, the biggest storyline heading into first pitch revolves around the status of Ketel Marte. If he is unable to suit up, it will place immense pressure on Corbin Carroll to jump-start the offense. Furthermore, with Carlos Santana and Pavin Smith both unavailable, corner infield depth is being tested for the Diamondbacks.