jon sebastiani: managing partner

Jon Sebastiani is a graduate of Santa Clara University with a Bachelor’s degree in Economics and holds a dual MBA from the Haas School of Business at UC Berkeley and Columbia University. His expertise in establishing and growing successful food brands has been cultivated through years of managing operations in previous positions, as managing partner of, President of the premier California winery destination Viansa Winery, and most recently leading the jerky renaissance as Founder of KRAVE Jerky. In 2016, following the acquisition of KRAVE Jerky by The Hershey Company, Sebastiani launched Sonoma Brands. Sonoma Brands is a one-of-a-kind consumer products incubator and venture fund, set to revitalize stagnant industry categories with innovation. Sonoma Brands has since invested in Dang Foods and has launched two brands under its incubator umbrella; ZÜPA NOMA and SmashMallow. For more information on Jon and Sonoma Brands, please visit


Theo runs business operations for the Stompers, including corporate partnerships, media/public relations, and front office management. He also mans personnel acquisition, development, and scouting. Theo negotiated the deal that made the Stompers the subject of the book “The Only Rule Is It Has To Work,” signed Jose Canseco to a two-day contract, and signed the first openly gay player in the history of professional baseball. Previously, he helped launch the San Rafael Pacifics, reported on the San Francisco Giants for the Bay Area News Group, and worked on ESPN events, including Sunday Night Baseball, the MLB All-Star Game, and Monday Night Football. He has won multiple awards for his work as a sports journalist.



KElsey minigan: Special assistant to the Managing Partner

As Consumer Relations Manager and Sonoma native, Kelsey truly defines & represents the Sonoma Stompers and Sonoma Brands as a community pillar. Excited to firmly establish her hometown as a hub of entrepreneurship, Kelsey manages every interaction as the first point of contact and plays a supporting, cross-functional role in the efforts of the Sonoma Brands team, and is the point person on all Stompers-related Managing Partner Jon Sebastiani.

Kelsey completed her BA in Environmental Studies at UCSB before heading back to the Bay to work for the San Francisco Giants in Luxury Sales & Client Relations. After the incredible 2014 season came to a close, Kelsey took a position with Yelp as an Account Executive in Sales. During her time there, she focused on helping over 3,000 small to medium sized businesses utilize Yelp as a tool to support growth – and will likewise support the Sonoma Brands portfolio.

Brett Creamer: Assistant General Manager

Brett, who is now in his fourth season of Professional Baseball returns to Sonoma for the first time since their inaugural season in 2014, where he was Director of Game Day Operations and Community Affairs. Since his departure, Creamer has worked three seasons for the Golden State Warriors where he has assisted with Arena Operations, Special Events, Sponsorship Activations, and Community Foundations. He also has one year of MLB experience with the Oakland Athletics where he is a Ticket Taker Supervisor.  The former Bowling Green State University Sport Management Graduate currently resides in his hometown of Petaluma.  


JOEY SAMUELSON: Assistant General manager of operations

Joey Samuelson is a Sonoma County native in his first season as Assistant General Manager for the Stompers. A Business Management student at Sonoma State University, Samuelson will graduate with a Bachelor’s of Science degree in the fall.  Joey has a passion for baseball and aspires to have a successful career in sports upon graduation from SSU.



HAYLEY M. SLYE: director of MEDIA RELATIONS and marketing

Hayley M. Slye is in her first season with the Sonoma Stompers. A graduate of Cal State Fullerton, Slye served as the Editor-in-Chief and sports editor of her college newspaper. Her sportswriting work has won two California Newspaper Publisher Association awards and has been published in Baseball Prospectus, Sports Illustrated online and You can follow her on Twitter here.



Geoff safford: director of broadcasting

The Sonoma County native has been with the Stompers for two years and is entering his first full season as the radio voice of the Stompers. Last season, he worked with the Stompers as a media relations assistant to the long-time broadcaster Tim Livingston. He came to Sonoma with broad range of experience in broadcasting. He got his start in 2007 when he broadcasted his local high school’s football games on a local TV station. He Studied broadcast journalism at both the University of Oregon, and Dominican University of California. 

While at Dominican, Safford was the voice of Penguin Athletics. He was the lead play-by-play man for men’s and women’s basketball as well as softball. He also worked for the Golden State Collegiate Baseball League as the league broadcaster for two seasons while in school. 

james w. toy III: team photographer










Tim assists the general manager and coaching staff in player evaluation and scouting. He also broadcasts for the Stompers on and on the TuneIn Radio app, which is available on Apple and Android devices. He will also broadcast select games on SVTV 27 Comcast Cable. He was previously the voice of Sonoma Valley High School sports, University of San Francisco Baseball and the Dunedin Blue Jays. He has also worked as a producer and editor at KTVU-2 FOX in Oakland.




Sierra m. heil: group event coordinator and director of ticket sales

Sierra M. Heil is in her first season with the Stompers. She is currently enrolled at Clemson University in South Carolina where she is double majoring in Marketing and Sports Communications. Heil is an active member of the Clemson Marketing Association and works with the Clemson Athletic Department as well as the 2016 National Champion Clemson Football Team.



Trey Dunia is the voice the Sonoma Stompers at Peoples Home Equity Ballpark at Arnold Field. A member of the National Association of Sports Public Address Announcers, his voice is well known in the Sonoma County sports scene. In addition to announcing for the Stompers, he also currently announces for Santa Rosa Junior College, the North Bay Rattlers football team, Analy High School, the West County Tigers and numerous District 35 Little League teams.


Kayla Sibbaluca: Head Athletic Trainer

Kayla Sibbaluca graduated from San Jose State University with a Bachelors of Science Degree in Athletic Training.  She is currently studying for her Masters of Science Degree in Rehab Sciences at California University of Pennsylvania.  Sibbaluca previously worked as the Head Athletic Trainer at Petaluma High School for all school sports. She also worked with Sonoma State University as a Per Diem Athletic Trainer for club sports.  

Sibbaluca brings a wide range of experience that include working in high school, and college athletic settings. She also worked in a sports focused chiropractic clinic while in school. Her sports athletic training background made her the perfect choice as the Stompers head athletic trainer for the 2017 season. 

Kayla has just begun a partnership with Nova Performance Center in Petaluma, Calif. where she treats sports and fitness enthusiast of all levels.

LAURENCE J. ADAMS, DC, DACNB: Team Chiropractor

Adams has been the Stompers' team chiropractor since 2015, giving treatment to players both at the field and at his office in downtown Sonoma. Born and raised in Sonoma, Adams got his Doctorate in Chiropractic from Life Chiropractic West in 1996, graduating Summa Cum Laude. He did his graduate work at Brigham Young University, earning a degree in Health Sciences. His son, Dax, is regularly a bat boy with the Stompers.


Ben Lindbergh is a Special Assistant to the General Manager and a baseball writer at Ben Simmon’s The Ringer.  In the past, he has been a contributor at Bloomberg Sports, Grantland, and, in addition to serving as Editor-In-Chief at Baseball Prospectus, and was a staff writer with Nate Silver's FiveThirtyEight. He co-authored "Extra Innings: More Baseball Between The Numbers," won the SABR Greg Spira Award for his research on pitch framing, and wrote "The Only Rule Is It Has To Work" with Sam Miller about the 2015 Sonoma Stompers season. You can purchase the book here.


Sam Miller is a Special Assistant to the General Manager and staff writer for ESPN. Formerly the Editor-n-Chief of Baseball Prospectus, Miller has also written for ESPN The Magazine and the Orange County Register. He's the former co-host of the “Effectively Wild” daily baseball podcast with Ben Lindbergh, who is also his co-author for “The Only Rule Is It Has To Work,” which is about Sam and Ben’s 2015 boots-on-the-ground experience in the Sonoma Stompers front office. It can be purchased here.