It's at the umpire's discretion. Warnings are given and usually heeded to.
If the pitching change only lasts a minute, then when the hell am I supposed to get my $10 chicken basket?!
But in all seriousness, you can't change the way coaches change pitchers. Sometimes, the coach doesn't know he's making the change until he speaks with the pitcher. Sometimes, the coach is actually trying to piss off the umpire and get him to come to the mound so they can share a few words. The relief pitcher, even if he sprints like Cotton, will need more than a minute from the time he leaves the bullpen mound. "In the name of safety," he will never lose those ~8 warmup pitches, which I think is necessary for some places that have a completely different game mound than the shitty bullpen mound.
This post was edited on 6/24 at 2:36 pm