Mac Jones aggravates knee as 49ers take 20-7 lead

Mac Jones has been on the injury report with a knee injury for the past two weeks. He took a hard hit from Jared Verse on a 10-yard pass to Kendrick Bourne in the third quarter. The 49ers quarterback limped all the way down the field and then was in obvious pain on the next play when he pitched the ball to Christian McCaffrey.

Four plays later, on third-and-goal, Byron Young knocked Jones to the ground on an incompletion and landed on him. Rules analyst Terry McAuley said officials should have penalized Young for roughing the passer for landing his full body weight on Jones.

Jones remained on the ground, grabbing his left knee, with 6:36 remaining in the third quarter.

Jones, who is playing with a knee brace, jogged off the field as his teammates greeting him once he reached the sideline.

Adrian Martinez is the backup.

Jones is starting in place of Brock Purdy, who is missing his third game of the season with a toe injury. He is 18-of-28 for 214 yards and two touchdowns.

The 49ers lead 20-7, getting a 20-yard Eddy Piniero field goal after Jones' injury.

The Rams missed a 53-yard field goal on their first drive of the second half, with Joshua Karty kicking it wide right.