Monday’s series opener between the San Francisco Giants and the Arizona Diamondbacks sure brought the fireworks. A first-inning grand slam by Nolan Arenado set the tone for a 12-2 blowout by the Snakes. Now they’ll try to make it two in a row at home, while the Giants desperately try to recapture momentum.

First pitch is set for 9:40 p.m. ET. The Diamondbacks are -123 moneyline favorites on DraftKings Sportsbook, while a Giants upset is priced at +102. The game total is set at O/U 8.5 runs.

Let’s get into a pick and prediction for this Giants vs. Diamondbacks game.

Giants vs. Diamondbacks Preview

First things first, let’s get to know these starting pitchers.

Landen Roupp steps to the mound for the Giants. The 27-year-old has quietly been excellent since breaking into the major leagues, yet has been overshadowed by Logan Webb and the Giants’ oppressive mediocrity as a team. 2025 was Roupp’s first full season in the rotation, posting a respectable 3.80 ERA across 22 starts before injuries ended his season. This year, he’s taking it to a new level.

Roupp’s 3.49 ERA this year has been a tad unlucky; according to Baseball Savant, his expected ERA sits at 2.75. Sitting in the 90th percentile or higher in ground ball rate, hard-hit percentage, and barrel percentage, Roupp is doing a superb job at avoiding damaging contact. He does this by throwing a lot of sinkers, changeups, and relying heavily on his excellent curveball. Opponents have a ghastly .218 expected slugging percentage against that curveball, which he uses as his putaway pitch. But don’t get it twisted: all of his stuff is nasty.

Opposite him is another right-hander looking to build on a strong 2025. Ryne Nelson was one of the bright spots in a frustrating season for the Diamondbacks, and they hoped to see another step taken in 2026. Unfortunately, that step was taken backwards; Nelson has surrendered a 5.40 ERA through nine starts.

In many ways, he is the anti-Roupp; armed with a prolific four-seam fastball that sits around 96 MPH, Nelson has struggled to establish his breaking balls. While Roupp is 90th percentile or better in barrels, hard hits, and ground balls, Nelson is 14th percentile or worse in all three. Giving up hard-hit fly balls hardly plays anywhere, but it’s especially dangerous when half your starts are in Chase Field.

Both offenses have scuffled this year, but you wouldn’t know the Diamondbacks were struggling last night, hanging 12 runs on veteran starter Robbie Ray and a quality Giants bullpen. It’ll take a similar performance tonight against Roupp, and they’ll have to hope that SF won’t take advantage of Nelson’s struggles.

Now that we know these teams a bit better, who is going to take this one home?

Giants vs. Diamondbacks Pick, Best Bet

Even with Roupp on the mound, these Giants are awfully hard to trust. The offense has been bad, the defense continues to make brutal mistakes, and they haven’t found consistency from the bullpen despite the good overall numbers. Arizona will find a way to mitigate Nelson’s damage and bring home another win.

Best Bet: Arizona Diamondbacks Run Line -1.5 (+156)