Ken -- I'm certainly not taking anything personally -- I think your advice is a valid option and others are simply considering how communicating with HS coaches might work for their son.
I agree with Milk Mannorth and others that suggest that the freshman find a way to stretch on his own. Often times, there are enough "waiting minutes" before a game where he can stretch. Some go out into the outfield and run sprints, etc. My guess is that others will join him, which might lead to a larger team effort.
I often ride the fence on controversy -- I see both sides of the talk to the coach debate. I support direct conversation between the player and the freshman coach first, then escalation, if necessary. I also support a bit of a "practice session" with his parents if there is reluctance. Despite being criticized here for all manner of behavior, I think most coaches are reasonable with players that show respect and maturity.
In any case, I think a kid will survive running (even if it seems excessive)....but he/she needs to stretch as well.
-PD