The San Francisco 49ers' quarterback carousel keeps spinning during Sunday's NFL Championship Game against the Philadelphia Eagles. Brock Purdy is back behind center after exiting in the first quarter with an injured elbow.

Purdy was forced back into action after fourth-string QB Josh Johnson was removed in the third quarter with what was later ruled a concussion, following a sack. Purdy suffered his injury on the 49ers' sixth offensive play of the game. The play was initially ruled an incomplete pass, but was later overturned to a fumble after the Eagles challenged.

Running back Christian McCaffrey would be the emergency quarterback, according to the Fox broadcast, but fullback Kyle Juszczyk was seen looking at the play sheet. 

Purdy was taken with the last pick in the 2022 NFL Draft, getting the nickname "Mr. Irrelevant." Since replacing the injured Jimmy Garoppolo, Purdy has gone undefeated, including two playoff wins. Garoppolo replaced Trey Lance at quarterback when the initial starter went down with a season-ending ankle injury.

As for Johnson, this marks the 36-year-old's first playoff appearance. A fifth-round pick in 2008, Johnson has been the ultimate journeyman, bouncing around the league while appearing in games for seven different franchises. The 49ers signed Johnson off of the Broncos' practice squad in December after Garoppolo went down.

This story will be updated as more information becomes available.