MIAMI GARDENS, Fla. -- The Miami Dolphins placed Tua Tagovailoa on injured reserve Tuesday after the quarterback was diagnosed with his third concussion in two years.

Tagovailoa will be sidelined for at least four games. He will be eligible to return in Week 8 when the Dolphins host Arizona, but has to complete a series of tests and assessments required by the NFL's concussion protocol before he can return to the field.