Miami Dolphins quarterback Tua Tagovailoa left last night’s game against Buffalo because of a concussion after colliding with Bills defensive back Damar Hamlin and hitting the back of his head against the turf.   Tagovailoa, who has a history of dealing with head injuries, remained down for about two minutes before getting to his feet and walking to the sideline after the play in the third quarter. It was his 3rd concussion. He made his way to the tunnel not long afterward, looking into the stands, appeared to smile and departed for the Dolphins’ locker room. He signed a four-year, $212 million extension before this season and was the NFL’s leading passer in Week 1 this season. To add insult to injury, the Dolphins lost 31-10.