Washington Commanders quarterback Marcus Mariota suffered a sprained right knee and will miss the rest of the preseason, but he is expected to be ready for the regular-season opener.
Mariota sprained his medial collateral ligament in the first quarter of Friday's 20-7 preseason-opening win over the Miami Dolphins and will miss the final two exhibition games. He was unlikely to play in the Aug. 28 preseason finale at Baltimore but would have played in Saturday's game at Detroit.
Washington plays at Philadelphia in the season opener Sept. 13, and Commanders coach Dan Quinn said, "We're optimistic he'll be ready at that time."
On Friday, Mariota pivoted on his right leg while handing the ball off to rookie Kaytron Allen then limped off the field. After going to the medical tent, Mariota walked to the locker room and did not return.
Quinn said the Commanders are not bringing in another quarterback at this time.
Mariota, in his third season with Washington, has been a valuable backup to Jayden Daniels.
Mariota played in 11 games, including eight starts, last season, throwing for 1,695 yards, 10 touchdowns and seven interceptions. He replaced an injured Daniels in two games in 2024, leading victories in both games -- including a game-winning pass at Dallas in the regular-season finale with two seconds remaining.
Mariota has dealt with injuries in each of the past two training camps. He opened the 2024 season on injured reserve because of a strained pectoral muscle and did not play in last year's preseason because of a lower leg strain.
Meanwhile, Quinn said Nick Allegretti (strained calf), the favorite to win the starting center job, and tight end John Bates (hamstring) will practice Tuesday. Both have been out since the first day of camp July 29.
Starting cornerback Trey Amos returned to practice Aug. 7 after opening camp on the physically unable to perform list. But he injured his ankle in that practice, and Quinn said he is continuing to rehab. Amos fractured his fibula in Week 10 last season and dealt with a soft-tissue injury before camp.
Running back Jeremy McNichols will miss a couple of weeks because of a quad injury, Quinn said.