Mariota is expected to miss the rest of the preseason due to a sprained MCL in his knee, Adam Schefter of ESPN reports.
Mariota sustained the injury in the first quarter of the Commanders' 20-7 preseason win over the Dolphins on Friday. Sam Hartman and undrafted rookie Athan Kaliakmanis are the other two reserve quarterbacks on the training camp roster, so the Commanders could look to acquire another QB via free agency or trade to provide depth behind Jayden Daniels. Mariota will focus on rehab and recovery over the next few weeks, and head coach Dan Quinn expressed optimism Sunday that Mariota will be available for the Commanders' regular-season opener against the Eagles on Sunday, Sept. 13, per Nicki Jhabvala of The Washington Post.