Seattle Mariners at San Diego Padres odds, picks and predictions

The Seattle Mariners (8-11) and the San Diego Padres (12-6) wrap up a 3-game series Thursday at Petco Park in San Diego, California. First pitch is scheduled for 8:40 p.m. ET (MLB Network). Let's analyze MLB odds around the Mariners vs. Padres odds and make our expert MLB picks and predictions for the best bets.

2026 season series: Padres lead 2-0

The Padres won 7-6 as slight underdogs (-108) Wednesday against the Mariners, clinching the series win as the Over (8) cashed. SS Xander Bogaerts was 2 for 4 with a HR and 2 RBIs, while DH Gavin Sheets was 2 for 4 with a pair of doubles and a run scored. For Seattle, RF Luke Raley went bonkers, finishing 4 for 5 with a double, HR, 2 runs scored and 2 RBIs in a losing effort.

San Diego also won 4-1 Tuesday as a slight dog (+104) as the Under (7.5) hit. The Padres have won 7 in a row, outscoring the opposition 47-21 as the Over is 3-1 in the past 4 games, and 6-2 in the previous 8 outings. After a 4-game win streak, the Mariners have dropped 2 in a row, and they're now 5-9 in the past 14 outings. The Over is 4-2 in the past 6 games.

Mariners at Padres projected starters

RHP Luis Castillo vs. RHP Walker Buehler

Castillo (0-0, 6.92 ERA) will make his fourth start of 2026. He has a 1.77 WHIP, 2.8 BB/9, 9.7 K/9 in 13 innings.

• Last start: No-decision, 3 1/3 IP, 7 ER, 10 H, 1 BB, 3 K in 8-7 home win vs. Houston Astros Saturday
• 2026 on road (1 start): No-decision, 3 2/3 IP, 3 ER (4 R), 6 H, 1 BB, 4 K in 8-7 loss April 5 vs. Los Angeles Angels in 11 innings
• Career vs. Padres: 3-3, 3.71 ERA (51 IP, 21 ER), 7 HR, 15 BB, 55 K, 1.20 WHIP, 9.7 K/9 in 9 starts

Buehler (0-1, 4.97 ERA) will make his fourth start of 2026. He has a 1.26 WHIP, 3.6 BB/9 and 7.8 K/9 in 12 2/3 innings.

• Last start: No-decision, 6 IP, 0 ER, 3 H, 0 BB, 4 K in 5-2 home win vs. Colorado Rockies Friday
• 2026 at home (2 starts): 0-1, 2.70 ERA (10 IP, 3 ER), 1 HR, 2 BB, 7 K
• Career vs. Mariners: 1-1, 7.08 ERA (20 1/3 IP, 16 ER), 5 HR, 10 BB, 19 K, 1.57 WHIP, 8.4 K/9 in 4 starts

Mariners at Padres odds

Provided by BetMGM Sportsbook; access USA TODAY Sports Scores and Sports Betting Odds hub for a full list. Lines last updated at 1:46 p.m. ET.

• Moneyline (ML): Mariners -120 (bet $120 to $100) | Padres +100 (bet $100 to win $100)
• Run line (RL)/Against the spread (ATS): Mariners -1.5 (+140) | Padres +1.5 (-170)
• Over/Under (O/U): 8.5 (O: -105 | U: -115)

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Mariners at Padres picks and predictions

Prediction

Padres 5, Mariners 4

Moneyline

The PADRES (+100) are a great option at even-money. The Padres haven't been getting great pitching from Buehler, but the Mariners haven't been getting great efforts from Castillo, either. In fact, he has really struggled in his past 2 outings.

Side with the home side as as better value.

Run line/Against the spread

If you're a very conservative bettor, and you can't take San Diego straight up, back PADRES +1.5 (-170) catching a run and a half for some insurance. It isn't priced out of line. It's personally not my favorite play, as I'd rather just go straight up.

Over/Under

OVER 8.5 (-105) is the lean, but go lightly.

Both of these pitches have been very giving. In fact, while Petco Park isn't a hitter's park, going OVER 4.5 - FIRST 5 INNINGS (-130) is a strong play, too.

For more sports betting picks and tips, check out SportsbookWire.com and BetFTW.

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