Coaches

Jon Tessier enters his first season as the Mill Rats Pitching Coach, bringing a diverse background in collegiate athletics, player development, and baseball analytics. Born and raised in San Diego, California, Tessier adds a broad geographic and baseball perspective to the Mill Rats coaching staff. In addition to his role with the Mill Rats, he also serves as the Pitching Coach for the California Post-Graduate Baseball Program, working closely with athletes preparing for collegiate opportunities. Tessier also serves as an Assistant Coach for the College of the Desert Roadrunners, a junior college located in Palm Springs, California.

Tessier has gained valuable experience in the summer collegiate baseball landscape, previously coaching in the Palm Springs Collegiate League (PSCL). During his time in the PSCL, he also ran the organization’s analytics department, managing and operating TrackMan and Rapsodo technology to support player development and collegiate recruiting. Tessier has also worked in collegiate athletic recruiting with SportsForce Baseball, providing him with valuable insight into the recruiting process and player placement at the next level.

Tessier played collegiately for the Lions of Eastern Nazarene College (NCAA Division III) in Quincy, Massachusetts. During his career, he helped lead the Lions’ pitching staff to back-to-back New England Collegiate Conference (NECC) Championship appearances in 2022 and 2023. His collegiate career was highlighted by multiple All-Conference selections and Academic All-Conference honors in all four seasons, reflecting excellence both on the field and in the classroom. Tessier recorded the first victory over a nationally ranked opponent in program history, throwing a nine-inning complete game in a 7–1 win.

Tessier earned a Bachelor of Science in Sports Management and Business Administration from Eastern Nazarene College. He later continued his education at Point Loma Nazarene University, earning a Master of Business Administration (MBA). He brings a combination of competitive playing experience, player development expertise, and analytical thinking that allows him to contribute meaningfully to the success of the Mill Rats pitching staff.

Playing:
2017-2019 (3B, 1B, C) at Jeannette High School
2017 WPIAL Champion at Jeannette High School as a player (WPIAL- Class A)1 college semester of playing experience:
Waynesburg University, Fall 2019 (NCAA-DIII)
*played with Mason Miller

Coaching:
2021-Present – Volunteer Assistant Baseball Coach at Jeannette High School (WPIAL- Class A)
2025-2026 – Head Baseball Coach at Jeannette Middle School
2022-2024, 2025-current – Full-Time Volunteer Baseball Coach and Coordinator of Video & Analytics at Seton Hill University (NCAA-DII)

Education:
B.S. – Sports Management
M.B.A. – Leadership & Management
Both from Seton Hill University