Most advanced (eg college, tourney-level, pro) players begin their warm ups with some form of mini-tennis, but only with their teammates or coaches prior to the pre-match warm up with their opponent(s). You should not expect your league or tourney opponents to begin the immediately-before-the-match warm up with mini-tennis. Do not even ask. It's just not cool.
Full disclosure: I am a 4.5 USTA player and mini-tennis afficionado. There, I said it.