San Francisco Giants vs Arizona Diamondbacks Prediction, Odds and Picks for Today, 09/15/25

The Giants and Diamondbacks begin their final series of 2025 on Monday night at Chase Field. These teams met last week in San Francisco with the Giants taking 2 out of 3 games from the D-Backs. Zac Gallen will take the ball for Arizona after struggling against San Francisco last week. The veteran right-hander allowed 5 earned runs over 6.2 innings of work. It was his worst start since the middle of July, and the veteran right-hander has been better down the stretch this season. He’s been good against the Giants in his career, having allowed just 83 hits in 102.2 innings against them. Look for Gallen to put together a better outing in this one.

Opposing Gallen on the mound will be San Francisco’s Kai-Weng Teng. He will be making just his sixth career big league start, and has struggled up to this point. Teng owns a 7.54 ERA in 22.2 innings this season, and he posted a 9.82 ERA over 11 innings in 2024. It’s a small sample size, but it appears that Teng is still adjusting to life at the MLB level. Despite trading away some big bats at the trade deadline, Arizona’s offense has been steady down the stretch and should be able to give Teng some problems. Coming back home after a 6-game road trip, look for Arizona to find the win column in this one.

Giants vs Diamondbacks prediction: Diamondbacks ML (-140) available at time of publishing. Playable at that number.