Athletics vs. Diamondbacks Prediction, MLB Picks for Tuesday, July 21

The first pitch of the matchup between the Athletics (43-57) and the Arizona Diamondbacks (51-49) is set for 9:40 p.m. ET on Tuesday, July 21, with the Diamondbacks favored and returning a 1.66x payout to win, via PrizePicks.

The Athletics took the first game of the series. Tied 2-2 going into the seventh inning, 2B Jeff McNeil came in to pinch-hit and knocked a 2-RBI single to break the game open for the A’s, which would eventually lead to a 5-2 win. They have a chance to take the series against the Diamondbacks, who are starting a pitcher making his major league debut.

Below, we'll break down our Athletics vs. Diamondbacks prediction and picks for Tuesday’s MLB matchup, including the run line, over/under, and key player picks for PrizePicks.

Make your Athletics vs. Diamondbacks prediction on PrizePicks for tonight’s game.

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Athletics vs. Diamondbacks Prediction, Winner Payout, Over/Under – Tuesday, July 21

The Athletics will start Jack Perkins (4.11 xFIP in 57.2 IP, 24 appearances, 6 starts). Perkins started the season in the bullpen, and although he had a 5.46 ERA, his 3.46 xERA shows he might have been just the victim of some bad shakes. The move to the starting rotation has unfortunately not gone well, though (8.10 ERA, 5.08 xERA).

The Athletics are crumbling fast as this team is firmly in the middle of a rough patch. They enter today having lost 19 of their last 24 games, going from 0.5 games back in the American League West to 7.5 games out.

The A's aren't looking good for a Wild Card berth, either, sitting 8.5 games out of that final spot.

For the Diamondbacks, SP Kohl Drake (5.74 xFIP in 66.1 IP, 17 appearances, 16 starts in MiLB) will be making his MLB debut. The southpaw was acquired in the SP Merrill Kelly trade with the Rangers.

His fastball can reach the upper 90s, but his two best pitches are his curveball (with excellent downward movement) and his changeup, which has up to 15 inches of horizontal movement.

The good news for the D-Backs is they're in second place in the National League West. The bad news is they're 11.5 games back. They entered the All-Star break on a positive note with a sweep of the Dodgers, but they barely made a dent in the standings.

Their best chance at a playoff spot might be through the Wild Card, as they are only 0.5 games out of that slot.

Athletics vs. Diamondbacks Winner Payout, Over/Under – Tuesday, July 21

The Diamondbacks enter Tuesday’s game as home favorites against the Athletics, returning a 1.66x payout if they win outright, via PrizePicks Team Picks.

Here are the full payouts for the Athletics vs. Diamondbacks game on PrizePicks.

• Spread: Arizona Diamondbacks -1.5 (2.38x payout)
• Over/Under: 9.5 (1.85x payout on Over)
• Game Winner Payout: Athletics 2.12x | Diamondbacks 1.66x

Play the Athletics vs. Diamondbacks spread or over/under on PrizePicks Team Picks to earn real money — available in 35 states!

Team Picks data is live at the time of writing and is subject to change.

Athletics vs. Diamondbacks Prediction on Winner – 7/21/26

Here are the key game stats and trends behind our Athletics vs. Diamondbacks prediction on the winner for Tuesday, July 21.

Lock in your Athletics vs. Diamondbacks prediction on PrizePicks now.

Unless otherwise noted, data used in this article is from Baseball Savant or FanGraphs.

• The Athletics have lost eight consecutive road games.
• The A’s have lost Perkins’ last four starts.
• The only other start Perkins has made against the Diamondbacks was on August 3 of last season, in which he allowed 4 earned runs in all of 3 innings.
• The Diamondbacks have a 32-15 record against teams under .500, and that winning percentage (.681) is the best in baseball.
• The Athletics’ bats struggle away from Sacramento; their .289 wOBA and .125 ISO on the road rank dead last in the sport.

Athletics vs. Diamondbacks Picks, Player Stats for PrizePicks: 7/21/26

Here are the top Athletics vs. Diamondbacks picks to target on Tuesday, July 21. Today’s MLB picks for PrizePicks include Jacob Wilson and Gabriel Moreno.

Athletics SS Jacob Wilson vs. Diamondbacks: 1.5 Total Bases

• Wilson is entering this game red hot, having a hit in eight straight games, recording multiple hits in six of them.
• The A’s shortstop is one of the best at making contact, as his 14.7% whiff rate ranks in the 94th percentile and his 11.6% strikeout rate is in the 96th percentile.
• Wilson’s .276 xBA is in the 84th percentile. That could benefit him against a Diamondbacks pitching staff that ranks 29th, allowing a .263 xBA.
• Wilson has more success against left-handed pitchers, boasting a .149 ISO compared to .112 against right-handed pitchers. He also has an 8.8% strikeout rate against southpaws compared to 12.5% against righties.

Add Jacob Wilson to your PrizePicks Lineup now.

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Diamondbacks C Gabriel Moreno vs. Athletics: 5 Hitter Fantasy Score

• Moreno is having a banner year, owning career highs in xBA (.290), barrel rate (7.3%), and wOBA (.365).
• The Diamondbacks’ catcher rarely swings and misses, evidenced by a 16.2% whiff rate that's in the 90th percentile. That could be a problem for Perkins, whose 27.2% whiff rate is in the 65th percentile.
• The four-seamer and sweeper account for 71% of Perkins’ pitches to right-handed hitters. The righty Moreno has a .352 xBA and .525 xSLG against the sweeper and a .295 xBA and .526 xSLG against the four-seamer.
• Moreno performs far better against right-handed pitchers than left-handed pitchers; he has a .379 wOBA against righties and a .318 wOBA against southpaws.

Add Gabriel Moreno to your PrizePicks Lineup now.

Make Athletics vs. Diamondbacks Picks on PrizePicks

The A’s got a much-needed win in the first game. The Diamondbacks will rely on the arm of Kohl Drake, who is making his MLB debut, to tie this series and potentially move into a playoff spot.

Don’t wait until the first pitch happens — make your Athletics vs. Diamondbacks picks on PrizePicks now and earn real money if you’re right.

Pick players, predict More or Less on their stats, and cash in if you’re right. With Team Picks, you can make predictions on MLB game winners, spreads, and over/unders, now available in 35 states.

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