SF Giants will need to rely on young pitcher depth is rotation is complete

The SF Giants might be done making additions to the starting rotation after reportedly adding Tyler Mahle on a one-year deal. If this is it, they will need to rely on their young pitching depth to get through the 2026 season.

SF Giants will need to rely on young pitcher depth is rotation is complete

Teams no longer rely solely on five pitchers to start 162 games. They need that depth chart to run eight or nine starting pitchers deep.

The 2012 Giants were very much the exception to a rule that has changed over the past 15 years. Their top five starters including Madison Bumgarner, Matt Cain, Ryan Vogelsong, Tim Lincecum, and Barry Zito combined to make 160 of the 162 starts that season.

Can you guess who made the other two starts? Yusmeiro Petit is a great guess, and you would have one of those two pitchers correct. The other was Eric Hacker.

The current iteration of the Giants' rotation consists of Logan Webb, Robbie Ray, Landen Roupp, Adrian Houser, and now Mahle. Webb has been one of the premier workhorses over the past five seasons. He continued that trend in 2025 by leading baseball in both starts (34) and innings pitched (207).

Ray was surprisingly durable in his first full year back from Tommy John surgery. He made 32 starts across 182.1 innings while earning his second NL All-Star nod. However, he dealt with fatigue late in the year and was far less effective in the second half.

Roupp has a relatively low innings threshold, as he completed 106.2 innings last year. That was just shy of his career high as a pro, which was 107.1 innings set back in 2022.

Houser has made more than 25 starts in a season just once in his career, but has never completed more than 142.1 innings. The Giants can reasonably expect him to surpass 100 innings with ease, even if the projected numbers may not be that encouraging.

Mahle has made just 24 starts over the past three seasons. He underwent Tommy John surgery early in the 2023 season, which kept him on the shelf until late in the 2024 season. He made 16 starts in 2025, but spent a lot of time on the injured list with shoulder fatigue.

There are volume gaps in this rotation that will need to be covered by the younger depth. Hayden Birdsong, Trevor McDonald and Blade Tidwell are some of the pitchers that fall under this umbrella. The additions of Houser and Mahle likely mean that there will be no clear path for any of these three to open the season in the rotation. That said, injuries are part of the game, and teams need to have depth to weather that storm. The opportunities will be there for those three young arms to take advantage.

This is not the most durable rotation unit, and the Giants will need to be realistic about how many starts they can expect from Roupp, Houser, and Mahle. If they exceed those expectations, then that is great news. The baseball season is a long one, and the good teams have a plan in case pitchers miss time.