Can a hard-throwing reliever become the SF Giants closer in 2026?

Hard-throwing SF Giants reliever Joel Peguero was a pleasant surprise in 2025. Can he take over as the team's closer next season?

Can a hard-throwing reliever become the SF Giants closer in 2026?

The bullpen is one of the top areas the Giants need to address this offseason. In the final two months of the year, it was an open audition for next season and few relievers ran with the opportunity.

Joey Lucchesi and Matt Gage threw well enough to be penciled into next year's bullpen. It helps that both throw from the left side and were quite effective against left-handed hitters. Gage allowed a .591 OPS in same-sided matchups, compared to a .598 OPS from Lucchesi.

They will join Erik Miller in that role. However, Miller missed the second half of the season with an elbow sprain. It helps to have left-handed pitching depth.

Ryan Walker will likely return in some role, even if it is not as the closer. The Giants hope that he can have a bounceback season.

Then, there is Joel Peguero. He got an opportunity with the Giants after a strong stretch with the Sacramento River Cats.

Overall, Peguero pitched to a 2.42 ERA, 3.85 FIP, 1.03 WHIP, 6.9 K/9, and a 2.13 SO/W rate. The number that sticks out is the 6.9 K/9 rate.

The righty pitcher has an 8.4 K/9 rate in four seasons in Triple-A, so he never really tallied high strikeout totals in the upper minors. Not surprisingly, that number declined against major league hitters. This is a bit odd given that he throws a fastball that can easily reach triple digits.

So, could he become the team's closer? He has the premium velocity that teams often associate with closers, but the strikeout rate remains unusually low.

This could be a function of pitch mix. Peguero's four-seamer does not miss many bats and has been largely ineffective. He throws a sinker that is effective at inducing ground-ball contact, but that pitch is not often designed for high strikeout totals. It can be, but most pitchers use it for contact.

The 27-year-old pitcher has a slider that generates a healthy 37.0 percent whiff rate. There is a case to be made to de-emphasize the four-seamer in favor of the slider.

That said, Peguero only has a 22.1 percent whiff rate and a 23.3 percent chase rate. This means that he is getting hitters to chase or swing-and-miss at a well below average rate. That is usually an area where closers tend to excel.

Peguero has the fastball to thrive in that role. To become a closer, he will need to strike hitters out at a much higher rate. Pitching coaches can influence that by changing pitch mixes, mechanics, or some combination of both. While Peguero had a solid showing for the Giants, it is hard to picture him succeeding in a higher-leverage role without a notable bump in strikeouts.