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The San Diego Padres are looking to stay perfect against the Seattle Mariners this season as they go for a second three-game sweep on the road at T-Mobile Park on Sunday Night Baseball. The Padres took a 7-4 victory in Seattle behind a three-run home run by Nick Castellanos on Saturday to follow up on a 2-0 triumph in the series opener Friday. George Kirby (5-2, 2.84 ERA) is set to start on the mound for the Mariners against fellow right-hander Lucas Giolito, who went 10-4 with a 3.41 ERA in 2025 with Boston and is making his season debut.    

Sunday Night Baseball first pitch is set for 7:20 p.m. ET in Seattle. The latest Padres vs. Mariners odds list the Mariners as -165 home favorites on the money line. San Diego is a +138 underdog, and the Over/Under for total runs is set at 7.5.       

SportsLine MLB expert Angelo Magliocca has dug into the odds and found some value plays to create his best same-game parlay for Sunday Night Baseball, and any prospective bettors wanting to tail his Mariners vs. Padres picks should be sure to use the latest DraftKings promo code.

Magliocca, also known as "Amags," is a hugely profitable MLB capper who uses his deep knowledge of baseball to find value on player props, sides and totals. He is coming off another strong season at SportsLine. Over the 2022, 2023, 2024 and 2025 MLB seasons, Amags is up 133.4 units on straight bets and parlays while winning an additional 25.3 units on ladder plays. 

Here's a look at his best same-game parlay for Padres vs. Mariners on Sunday Night Baseball.

Padres vs. Mariners same-game parlay

Same-game parlay odds: +140 DraftKings (0.5 units)

Lucas Giolito makes his debut for the Padres after finally signing a free-agent contract, as he was still sitting on the sidelines until San Diego came calling. He faces off with George Kirby of the Seattle Mariners, who has been solid of late, creating a rather large starting pitcher discrepancy in this matchup. 

Giolito made four starts in minor-league ball, getting up to 74 pitches in his most recent outing while covering a full six innings, so he should see a normal starter's workload tonight. He was solid over those six innings, allowing just three hits and a run, so I wouldn't doubt if he turns in a strong five innings. That has me looking to the Under, thanks to how stagnant the Seattle offense has looked over the last couple of nights, and with George Kirby taking the ball on the other side for the Mariners.

Kirby is pitching to a 2.84 ERA, with his expected stats backing up the strong performance thus far. The strikeout rate has dropped below eight per nine innings for the first time in his career, but he's still finding ways to get hitters out. Kirby has held opposing offenses to two or fewer runs in six straight starts, so the first half Under at an alternate line of 5.5 interests me, but I'm going to take the full game Under with how good these bullpens can be and the uncertainty of what we get from Giolito. 

If he blows up completely, then we're likely going to lose the Under, but bumping this total up to 10 runs in a game with a 7.5 line currently is going to give us a bunch of extra wiggle room. I have this one projecting under the total of 7.5 anyway, and aside from a Nick Castellanos three-run homer yesterday, the Padres have scored just six runs across 18 innings this weekend, thanks to the struggling Fernando Tatis Jr and Manny Machado. The veteran third baseman has been brutally bad, and is now hitting below .200 on the year, so I could see this one becoming an old fashioned pitcher's duel. 

Kirby has been worse against right-handed batters, and this Padres lineup will likely roll with six righties, so I stayed off the Padres team total under and went with the full game instead.

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The Mariners have yet to use closer Andres Munoz or setup man Eduard Bazardo in this series, and after losing the last two nights, they should be fully ready to help the Mariners salvage at least one win here before welcoming the red-hot White Sox to town tomorrow. 

The Padres bullpen also should have Mason Miller ready to go, and with the starting pitcher matchup, I'm going to bet that the Mariners lead or at worst keep things close, to win or lose by one run. Adding the +1.5 for the home team who has the better starting pitcher and a rested bullpen fits well into how I see this game playing out.

Julio Rodriguez to strike out at least once tonight is actually showing some value even at the -200 price, and that's likely due to Lucas Giolito pitching on the other side. Giolito did strike out nine right-handed batters in eight innings in his rehab starts, though, and Rodriguez has just three games in May without at least one strikeout. 

Adding in how incredible that San Diego bullpen is and Julio hitting at or near the top of Seattle's order, I'm adding that prop into the parlay to get us to +140 odds and qualify for boosts. If you don't care about the boosts and want to take this one out to make it just run the total and +1.5, I think that's a solid move.

Be sure to check out the latest BetMGM promo code before you wager on Mariners vs. Padres and other MLB games.