The Washington Commanders placed Marcus Mariota on injured reserve on Saturday, meaning he will be out for at least the first four games of the season.
Coach Dan Quinn explained that Mariota has a strained pectoral muscle. The 30-year-old quarterback missed practice this week and was listed with a chest injury.
Journeyman Jeff Driskel is expected to be the backup for Jayden Daniels in the season opener on Sunday at Tampa Bay.
The Commanders have also signed former Notre Dame and Wake Forest QB Sam Hartman from their practice squad and moved defensive tackle Sheldon Day and linebacker Nick Bellore to the active roster for the game against the Buccaneers.
Rookie defensive tackle Johnny Newton is doubtful as he recovers from foot surgery done in the offseason.
Washington signed Mariota to a one-year, $6 million contract before drafting Daniels with the second pick. The 2015 No. 2 pick said at the time he was ready to either mentor or start, as needed.