Other mistake: When the cardiac arrest is first brought into the ER we hear "Let's get him intubated," but the weird subtitles read, "Let's get him elevated." Subtitles from Universal Studios 2010 DVD.
Other mistake: At the construction site, after Johnny administers the epinephrine to the cardiac arrest, 39's paramedic resumes CPR, and when they're lifting the patient onto the stretcher Johnny says, "Stop CPR," but the subtitles read, "Start CPR," which makes no sense since they've been doing CPR all along. Subtitles from Universal Studios 2010 DVD.
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 ★