Could a Sorcerer use Subtle Spell metamagic to cast while polymorphed?

@Gregtito Could a Sorcerer use Subtle Spell metamagic to cast while polymorphed, assuming the spell only requires V and/or S and not M?

— Thom Bly (@thomBLY) August 3, 2017

The polymorph spell prevents a transformed creature from casting spells. #DnD https://t.co/k7y5VqpqgM

— Jeremy Crawford (@JeremyECrawford) August 3, 2017