By Milo Taibi Miami Dolphins coach Mike McDaniel announced Wednesday that Tua Tagovailoa had been placed in concussion protocol. It’s Tagovailoa’s second stint in the protocol in the midst of a year filled with gruesome on-field injuries. While Dolphins fans are showing an outpouring of support for their quarterback, the NFL Players Association is investigating the circumstances surrounding Tua’s concussion. More specifically, the entity will look into how Tagovailoa’s concussion was handled after it occurred. Per NFL Network’s Tom Pelissero, an NFL representative had this to say of the invest…