The Los Angeles County Department of Public Health confirmed Friday that the coach had picked up the virus. The coach has not been at school since developing symptoms, school officials said.
The health department "advised us that there is only a small possibility your student has been exposed in this case," according to a letter to parents of the baseball team.
All baseball players have been immunized to the disease, school officials said.
The development comes as 59 California residents have come down with the virus since Dec. 2014, according to the health department. Health officials are urging unvaccinated individuals to get immunized.
List of potential exposure locations and times