The 6-3, 240-pound Castro has played with his hand down for Vista Murrieta the past two years, but now schools are envisioning him playing outside linebacker.
"I'm working on playing better in space and in coverage," said Castro. "I'll play wherever the school wants me. Either outside linebacker or defensive end."
Castro is planning to camp at Oregon and USC and attend Colorado's spring game. He camped at UCLA last spring, netting him an offer as just a sophomore.
"I'm not going to decide until the end of the season," said Castro. "I want to go through the process and take some visits."