Other mistake: When Station 51 is at the scene with the electrocuted man, he's dangling from a rope below the second stem of the letter H, in the large sign which reads "HOTEL", above the striped awning. In the shots from above the sign, looking directly down as they set up the ladder, we can see the letter H and the awning, but the dangling man is simply not there in the shots from this perspective, even though we should be able to see him.
Other mistake: When Engine 51 pulls up to the hotel with the injured man dangling from the hotel sign, Captain Stanley addresses Chet and says, "Chet, Roy and John'll need a line," but the subtitles read, "See that? Roy and Dan'll need a line, " even though there isn't anyone named Dan. Subtitles from Universal Studios 2010 DVD.
Other mistake: When the tones drop and Station 51 is dispatched to a "man injured", there is a closeup of the guys running from the kitchen into the apparatus bay, heading for the squad and engine, and none of them are actually 51's guys.
Other mistake: During the fire at the chemical plant, when Captain Stanley and Roy find the missing man and carry him out, the subtitles read that Johnny says "All right, grab his feet," when in fact it's Captain Stanley who says that - Johnny's not even in the same room with them. 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 ★