Tua Tagovailoa expected to be interviewed as part of NFL-NFLPA investigation into QB's quick return from injury, sources say

Tua Tagovailoa is expected to be interviewed early this week in the NFL and NFL Players Association's joint investigation of the injured Miami Dolphins quarterback's quick return to last weekend's game against the Buffalo Bills, sources told ESPN's Adam Schefter.

The league and players' association indicated Saturday that their review is ongoing while adding they agree that «modifications to the concussion protocol are needed to enhance player safety.»

A league official told Schefter that the investigation is expected to last another week or two, and the results will be announced «almost immediately after.»

Tagovailoa is expected to return to the Dolphins' facility Monday, sources told Schefter, as he continues to go through the concussion protocol after the head injury that forced him to leave Thursday night's game against the Cincinnati Bengals. Images of Tagovailoa's brain are being sent to three independent doctors to obtain as many opinions as possible about his condition.

Tagovailoa initially seemed to exhibit concussion symptoms after the hit to his head late in the first half of Miami's Week 3 home game against Buffalo, but he was cleared by a team physician and an unaffiliated neurotrauma consultant to return in the second half. Tagovailoa and the team later said his legs were wobbly because of a back injury.

After the Thursday hit, in which 6-foot-3, 340-pound Bengals defensive tackle Josh Tupou slammed Tagovailoa backward into the turf, the quarterback's hands froze up and his fingers flexed awkwardly in front of his face mask for several seconds as he lay on the ground in Cincinnati. He remained on the ground for several minutes until he was taken away on a stretcher and sent to a hospital. He was released