Sean Sullivan focusing on a team-first mindset

Sean Sullivan spent about three weeks at Driveline Baseball in Washington during the offseason. The University of California right-handed pitcher wanted to visit the world’s top data-driven development facility to learn more about pitching.

Teammates Ian Villers and Sam Stoutenborough joined Sullivan on the trip. The three Cal pitchers learned about throwing programs, PlyoCare drills, Rapsodo and Trackman equipment and data, and other ways they can improve on the mound.

They sought feedback and information that they could implement in their games and teach their Cal teammates. The experience was extremely beneficial, Sullivan said.

“Their main thing up there is building arm strength and putting stress on the ligaments and tendons that are in your arm that get a lot of stress when you throw, so they get used to the high intensity,” Sullivan said. “It has really helped with arm strength and injury prevention.”

Sullivan believes learning at Driveline will positively impact him this season.

This season is an important year for Sullivan, who professional scouts consider to be a well-regarded prospect for July’s MLB draft.

Sullivan didn’t receive any draft interest as a senior at Chaminade College Preparatory in California in 2018. But after adding about 25 pounds to his frame and improving his skills on the mound over his last 2½ years at Cal, Sullivan has a chance to be a top-five-round pick in this year’s draft.

“I have spoken to some scouts, and they came out in the fall to watch me throw some bullpens,” Sullivan said. “A lot of people focus on that a little too much. That’s not something I want to worry about. The priority is winning with my team. But I am excited if I get that opportunity. That is going to be awesome.”

Sullivan pitched primarily out of the bullpen his freshman season. He made 21 appearances (two starts), posting a 5.88 ERA with four saves, 29 strikeouts and 16 walks allowed in 26 innings.

During his freshman season, he also made one plate appearance. On March 17, 2019, Sullivan came in against Southern California in relief. After the Golden Bears’ designated hitter replaced their starting catcher, who the umpires ejected, the Golden Bears had to use the pitcher in the batting lineup. Sullivan came to the plate and hit a home run in his only at-bat.

“I hadn’t hit in like three years,” Sullivan said. “But, I wasn’t nervous and was going to swing the pitch if I got a good pitch. I got the count 2-2 and fouled a couple of pitches off. He hung a changeup, and I decided to swing at it. It just snuck out of there. It barely cleared the fence.”

In summer 2019, Sullivan thrived in the Cape Cod League as a starting pitcher. He posted a 2.08 ERA with 48 strikeouts and seven walks allowed in 43 1/3 innings (10 starts).

Last season, Sullivan made only two starts. He missed time due to an offseason injury after he tweaked his back lifting. In the pandemic-shortened season, Sullivan posted a 1.59 ERA with three strikeouts and four walks allowed in 5 2/3 innings.

Sullivan hopes he can build on last year’s limited sample size in a full season this spring.

On the mound, Sullivan is a 6-foot-1, 175-pound right-hander who throws a four-seam fastball, slider, spike curveball and changeup from a three-quarters arm slot and long arm action.

Out of high school, Sullivan was primarily a fastball-slider pitcher. While those two pitches remain his best offerings, he also has added secondary pitches that flash potential.

His top pitch is his slider. It is a hard-breaking offering that serves as his strikeout pitch. He has confidence in his slider and locates the pitch well.

His four-seam fastball also is a quality pitch. It sits in the low-90s but has the potential to develop into an above-average offering if he can increase the velocity.

“I think I am pretty athletic,” Sullivan said. “That is where I get most of my velocity is by being athletic. It’s just huge for me.”

In the offseason, Sullivan developed the curveball. He started throwing it after his sophomore season ended and worked on it while at Driveline. His changeup also is a developing offering, as he just started using it in college.

Besides improving his fastball velocity and refining his secondary pitches, Sullivan hopes to serve as a team leader this season.  

“Grant Holman and I have taken the initiative and started to lead the staff this year,” Sullivan said. “We really want to emphasize command because we have a lot of young guys that don’t have a lot of college experience and are focused a lot on velocity. I think they just need to understand that guys at this level can hit 92 to 95 mph with no problem, unless you have some secondary pitches. I really want to work on being more of a leader and helping the young guys a lot.”

Sullivan is a team-first player who has high expectations for himself and the Golden Bears. He hopes the work the pitchers have put in this offseason will translate into games this season.

Sullivan believes the Golden Bears have the talent to boast a quality pitching staff that can play a role in leading the team to the NCAA tournament this season. 

“A staff ERA under 3.00, the lowest walks in the Pac-12 and consistently winning the even counts are areas I hope we can do,” Sullivan said. “I think focusing on those statistics is going to be important. Zeroing in on the little things will be big and make a big difference in our pitching staff’s success this year.”

Read more in-depth stories on top 2021 MLB draft prospects at Baseball Prospect Journal.

Video of Sean Sullivan

Dan Zielinski III has covered the MLB draft for six years. He has interviewed 253 of the top draft prospects in that period, including three No. 1 overall picks. Multiple publications, including Baseball America, USA Today, and The Arizona Republic, have quoted his work, while he has appeared on radio stations as a “MLB draft expert.” Follow him on Twitter @DanZielinski3.

Dan Zielinski III
Dan Zielinski III
Dan Zielinski III is the creator of the Baseball Prospect Journal and has covered the MLB draft since 2015. His draft work originally appeared on, a sports website he started in December 2011. He also covered the Milwaukee Brewers as a member of the credentialed media for four years. Follow him on Twitter @DanZielinski3.

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