Papi served as Fresno High's athletic director for 25 years and has coached baseball for 49 years - and is still coaching.
Dozens came out for the ceremony to honor the coach.
"It gives me goosebumps. I drove in this morning and looked as I hit the parking lot and just could not believe how many Papi field signs were up. I appreciate this very very much. It means a tremendous amount to me and my family," Papi said.
He credited Fresno High School's administration, staff, and his family for their support throughout his career.
Papi's son Jason works at the current head coach for the Warriors, with Ken as the assistant coach.