Washington Commanders quarterback Jayden Daniels left their game against the Carolina Panthers early Sunday afternoon with a rib injury.

Daniels left in the first quarter after taking some tough shots after running with the ball on their first drive, setting up a field goal and putting them up 10-0 after the defense opened the game with a pick 6. Daniels was seen grabbing his ribs as he stood up after a tackle. He was clearly in pain on the sidelines when working with trainers.

After trying to throw the ball a bit down the sideline, Daniels then left for the locker room. He hit his helmet hard on the ground as he left the field at Northwest Stadium.

Backup Marcus Mariota came in to replace him. Commanders said it was doubtful Daniels would return with a rib injury. Daniels went 2-of-2 for 6 yards through the air, and he had three carries for 50 yards on the ground going out.

Daniels has dominated this season, his first in the league after his Heisman Trophy campaign at LSU last fall. The rookie entered Sunday’s matchup with 1,404 yards and six touchdowns with just two interceptions while leading the Commanders to a 4-2 start. He has thrown for at least 230 yards in every game except his NFL debut, and he posted a four-game win streak before losing 30-23 to the Baltimore Ravens last week. Daniels went 24 of 35 for 269 yards with two touchdowns in that loss.

While Mariota struggled on his first drive — the Commanders went three-and-out and had to punt right away — he put together a five-play, 59-yard touchdown drive on his second timeout to push Washington’s lead to 17 . Running back Brian Robinson carried that drive with four runs, including his 8-yard touchdown that came after Noah Brown made a pass interference call to put the Commanders in scoring position. At that point the commanders had 118 of their 120 yards on the ground.

This post will be updated soon with more information.