Other mistake: When the self defense instructor tries to use Mrs. Pestone to demonstrate the flip, he puts his arm around her and covers her mouth, then it cuts to a shot of Squad 51 rushing down a street. This particular shot is from 5x8, "The Lighter-Than-Air Man," when Roy drives past the school kids and crossing guard.
Other mistake: During the singles club fire, after Johnny and Roy check the men's room upstairs, there's a shot of firemen in full turnout gear with hoses, and this footage is from the first season's pilot episode, "The Wedsworth-Townsend Act."
Other mistake: During the actual cliff rescue of the hang gliding accident victims, Roy and John are wearing hiking-type shoes with ridges on the soles, not their uniform shoes.
Answer: I was rewatching a few first season episodes of Charlie's Angels (1976), and in S1xE6 "The Killing Kind," I recognized the same actor. So, to finally fully answer your question, the two baseball players in School Days are played by Rod Perry and Sean Fallon Walsh.
Super Grover ★