Arizona Diamondbacks at San Diego Padres Picks and Prediction for Sunday, September 27, 2026

Petco Park in San Diego hosts the series finale of this three-game NL West rivalry set at 3:10 PM ET as the Arizona Diamondbacks (86-74) visit the San Diego Padres (89-71) in a Sunday afternoon rubber match with genuine NL Wild Card playoff seeding implications for both clubs. The Padres have taken the series lead heading into Sunday, and Arizona desperately need the win — their 86-74 record leaves them clinging to the final NL Wild Card spot by a razor-thin margin with days left in the regular season. Sunday's pitching matchup sends Mike Soroka to the mound for Arizona against a Padres starter yet to be confirmed — a TBA arm whose identity defines San Diego's competitive ceiling, while Soroka's proven contact-management profile gives the Diamondbacks the individual pitching quality to steal the series finale on the road. numberFire gives Arizona a 53.43% win probability — essentially a coin flip that the market reflects at approximately even money. Read on to find out who takes the series finale in our Diamondbacks vs. Padres prediction. Don't go down on strikes! Get our top MLB Predictions and increase your bankroll!

Soroka Has Rebuilt His Career in Arizona — and Sunday's Wild Card Stakes Give Him Maximum Motivation

Mike Soroka carries a 28-31 career record and a 3.77 ERA into Sunday's assignment — a 29-year-old Canadian right-hander whose career arc has taken him through Atlanta, Chicago, Washington, and now Arizona. The former 2019 All-Star pitched an immaculate inning on March 30, 2026, establishing his 2026 Diamondbacks tenure with one of the sport's rarest individual achievements. His sinker-slider combination has been one of the NL West's most reliable contact-suppression profiles all season, and the specific context of Sunday's game — Arizona needing a win to protect their Wild Card position in the final days of the regular season — gives Soroka the individual competitive motivation that September starts in playoff races specifically generate.

The Arizona Diamondbacks have hit the Game Total Under in 33 of their last 50 away games — a 66% road Under rate generating +14.55 units and a 27% ROI that is one of the most profitable single team-totals trends in the National League. That Under lean runs most directly through Soroka's start cycle, where his contact-management approach generates the quick-inning, low-baserunner starts that keep combined totals compressed even in road environments. The Diamondbacks have also hit the 1st Five Innings Team Total Under in 30 of their last 50 away games — a first-half lean that reinforces Soroka's ability to suppress scoring contribution from Arizona's side across the opening frames. The Diamondbacks have a money-line conversion rate generating +15.70 units and a 40% ROI. That remarkable road money-line record is the single most important organizational trend for anyone evaluating Arizona's Wild Card urgency — a team that wins on the road at that rate is competitive regardless of the individual pitching matchup or the home team's historical Petco Park advantages.

San Diego's Bullpen the Real Structural Edge

San Diego has not confirmed their Sunday starter — a rotation decision that reflects the organizational approach to a season finale series where the Padres have already clinched their playoff position and can manage their rotation with October in mind. The San Diego Padres have compiled a 47-27 record in games they were listed as the moneyline favorite — winning 63.5% of those games — and have hit the moneyline in 33 of their last 45 home games.

Whatever arm the Padres deploy benefits from Petco Park's 0.92 park factor and marine layer — the most run-suppressive individual venue environment in the National League — and from Mason Miller's bullpen security in the ninth inning. The San Diego Padres have hit the Team Total Over in 27 of their last 40 games — a 67.5% recent Over rate generating +12.15 units — and the 1st Five Innings Team Total Over in 14 of their last 18 games, an extraordinary 78% first-half Over rate. That Padres first-half Over trend runs directly against Arizona's road Under lean, creating the central totals market tension that makes Sunday's game-total the most analytically interesting individual bet on the afternoon NL board.

Fernando Tatis Jr., Manny Machado, and Jackson Merrill give San Diego the middle-of-the-order depth that generates the early-inning runs the Padres' Team Total Over record reflects — and a TBA starter receiving first-inning run support from that lineup gives the Padres' individual game-state the competitive identity that Arizona's road record must overcome to steal the series finale.

Diamondbacks vs. Padres Picks

• Money Line Pick: Arizona Diamondbacks

numberFire gives Arizona a 53.43% win probability — a slight edge that the approximately even money line reflects accurately. Arizona has hit the moneyline in 23 of their last 35 away games, generating +15.70 units and a 40% ROI. Soroka's proven contact-management quality against a TBA San Diego arm whose ceiling is unknown, combined with Arizona's Wild Card survival urgency that maximizes every player's individual competitive motivation, makes the Diamondbacks the correct side at essentially even money. Take Arizona.

• Over/Under Pick: Under 7.5 Runs

The Arizona Diamondbacks have hit the Game Total Under in 33 of their last 50 away games — a 66% road Under rate generating +14.55 units and a 27% ROI. Soroka's contact-management profile at Petco Park's 0.92 park factor and marine layer — the most run-suppressive individual venue environment in the NL — creates the bilateral scoring suppression where the Under is the structural lean regardless of the Padres' Team Total Over trend. The Under at -108 is the sharper individual value in a matchup where Soroka's 3.77 ERA and Arizona's overwhelming road Under record both point toward the same conclusion. Take the Under 7.5 runs.