Nelson has coached the track and field team at Mt. Pleasant High School in San Jose for 25 years. During that time, he has helped 40 students get athletic scholarships.
Among them is Texas A&M University sprinter Jeneba Tarmoh, who in 2008 won the World Junior Championship in the 100-meter race in Poland.
But just last month, Nelson was forced to transfer to Evergreen Valley High School.
"Yeah, it was very disappointing. I was shocked. I thought it was a joke at first but who am I to say what the district does," he said.
Even though he's been coaching for so long, he has only worked as a P.E. teacher at Mt. Pleasant for four years and there was a vacancy at Evergreen.
The Eastside Union High School District issued a statement saying, "We are following the contract that states a person with the least amount of seniority must be transferred to a different school when there is a vacant position."
Students have vowed to fight the district. Leading the group is Tiana Carter who this year will begin college at UC Irvine, thanks in part to Nelson.
"I was recruited by more than four different schools on scholarships for track," she said.
"He's changed people's lives, helped them go on to college, get scholarships to go out of state and helped change their work ethics that otherwise would not be up to par," Mt. Pleasant student Conner Frey said.
Students have collected signatures to try to keep nelson at Mt. Pleasant.
On Thursday, a group of students will deliver those signatures to member of the School Board, and they have agreed to take up the matter during their regular meeting.
"I have firm ties to the common at Mt. Pleasant, not just the kids but the whole community and my entire coaching staff are ex Mt. Pleasant athletes and right now we feel that we're in a state of limbo and don't know what to do," Nelson said.
Nelson and his team are hoping the district will re-consider.