The Miami Dolphins went down to their third-string quarterback Skylar Thompson against the New York Jets.

Backup Teddy Bridgewater sustained an elbow injury and head injury following a hit on Miami's opening drive on Sunday. He left the game, and the Dolphins initially listed him as questionable to return. He was later downgraded to out in concussion protocol.

With starter Tua Tagovailoa sidelined with a head injury, the Dolphins opened up their second series against the Jets with Thompson at quarterback. A seventh-round rookie out of Kansas State, Thompson made his NFL debut considerably sooner than expected.

He finished 19-of-33 for 166 passing yards and an interception as the Dolphins lost, 40-17, on the road.

Bridgewater's head hits turf

Bridgewater's injury took place on a dropback on Miami's first offensive snap of the game. Cornerback Sauce Gardner pressured Bridgewater in the end zone. His helmet made contact with Bridgewater's throwing elbow, and Bridgewater's head hit the turf at the completion of Gardner's hit.

Bridgewater was flagged for intentional grounding in the end zone, and the Jets scored a safety on the play. He entered a sidelined medical tent for evaluation after the hit, then walked to the locker room before the Dolphins eventually ruled him out.

New concussion guidelines factored into Bridgewater being ruled out

Miami's response to Bridgewater's potential head injury was under increased scrutiny following Tagovailoa's concussion against the Cincinnati Bengals. The Dolphins starter appeared to sustain a head injury in Week 3 against the Buffalo Bills, but returned to the game and started Miami's Week 4 game against the Bengals. He was then hospitalized with a head injury against the Bengals.

The NFLPA fired an independent doctor who cleared Tagovailoa to return against the Bills, and the NFL and NFLPA agreed on Saturday to stricter guidelines on a player's eligibility to return to the field after displaying concussion symptoms in the wake of Tagovailoa's injury.

Those guidelines played a factor in Bridgewater being ruled out Sunday. Per NFL Network's Ian Rapoport, Bridgewater passed concussion tests administered by doctors, but was ruled out based on the new guidelines.

The Palm Beach Post reported that a spotter saw Bridgewater stumble after the blow to his head.