no longer in question, the winning coaches should put in their scrubs so everyone can continue playing the game at 100%.

• The winning team protects their starters from unnecessary injury
• The scrubs get valuable reps
• Coaches should call in plays as they normally would. However, they shouldn't call any trick plays that they haven't called before.  Hold those cards close to the chest until they are needed.
• It's actually more respectful to put the scrubs in than to have the starters give a fractional effort.  Playing against someone that isn't trying is not fun.
• It's in the winning team's interest not to completely demoralize an opponent.  You want them to bounce back and win every game they have for the rest of the season.  That's just as beneficial in terms of "style points" as large margins of victory.  Putting in scrubs in helps the losing team's players recognize the things they are doing well.