SF Giants farm system: Updated top 31 prospect rankings

SF Giants prospects: Midseason 2021 rankings
20. Sean Hjelle, RHP

Age: 24
Highest Level: Triple-A (Sacramento)
Acquired: Draft (2018)
Future-Value Grade: 40+

Considered one of the most MLB-ready prospects in the 2018 draft, Sean Hjelle was one of the few “sure things” from a volatile SF Giants draft class. The towering seven-footer (he’s listed at 6’11”, but is actually 6’11.5”)  has a unique profile. Hjelle isn’t like other notably tall pitchers like Randy Johnson and Jon Rauch, who relied on premium velocity. Instead, he has shown excellent control and limited hard contact.

Hjelle projects to have four viable MLB offerings: a fastball, slider/cutter hybrid, curveball, and changeup. Depending on who you talk to, they all grade between fringe and average, with the exception of his curveball which should be an above-average pitch. None of his offerings project as plus, but his size adds a level of variability that could help them play up. We have never seen a pitcher like Hjelle before. That means big-league hitters will not have any experience facing someone like him either.

If he were an average height for a pitcher, he’d project like a right-handed version of Andrew Suarez—someone expected to move quickly with a shot to stick in the back of a rotation. Given the uniqueness of his delivery and the potential for him to add strength to his frame to increase his velocity, I believe he has more upside than most other prognosticators. However, he’s already reached Triple-A and that projection has yet to bear any fruit.

Hjelle began 2021 back at Double-A, where he struggled after a late-season promotion back in 2019. Hjelle quickly looked comfortable in the Richmond Flying Squirrels rotation and recorded a 3.14 ERA with 69 strikeouts and 19 walks across 65.2 innings pitched. The Giants have never hesitated to promote Hjelle aggressively, and they moved him up to Triple-A in August.

The Giants would love for Hjelle to force his way into their starting rotation, particularly as they have been depleted by injuries and COVID-19. Hjelle has completed at least five innings in all four of his starts at Triple-A and is inducing groundballs at a rate in line with his career numbers, but the righty has posted a 6.65 ERA with fewer strikeouts (9) than walks (13).

While Hjelle has all the pieces to be a big-league starter, he’s always performed dramatically better in the first three innings of his outings. Barring a significant improvement, Hjelle might find more success in a Yusmeiro Petit-like long reliever role than in the rotation.

He has to be added to the 40-man roster this offseason to avoid being selected in the Rule 5 draft. He’ll likely return to Triple-A to begin 2022 and assuming he finds more consistent success, he should make his big-league debut at some point next season.