The Las Vegas Raiders won't have quarterback Jimmy Garoppolo for their Week 4 divisional clash against the Los Angeles Chargers. Garoppolo, who has been in the concussion protocol, has been ruled out for the contest, per ESPN's Adam Schefter.

Garoppolo was able to take the practice field on Thursday and Friday, but he was unable to clear the concussion protocol in time.

As noted by ESPN's Adam Schefter, no player in the NFL has returned to play the week after entering the concussion protocol, with Garoppolo–as well as Indianapolis Colts QB Anthony Richardson and Miami Dolphins wideout Jaylen Waddle–the latest examples.

Garoppolo was listed as questionable, with Raiders head coach Josh McDaniels telling the media that the team was “at the mercy of the testing” and would “see if he clears.”

Now, the Raiders will have to turn to either Brian Hoyer or rookie Aidan O'Connell under center against the Chargers.

Given O'Connell's lack of experience and Hoyer's familiarity with McDaniels, one would have to expect the latter to get the starting nod on Sunday.

Las Vegas is 1-2, coming off of a tough loss to the Pittsburgh Steelers on Sunday Night Football this past week. Now, after two straight losses, the Raiders will look to get back into the winning column without their starting QB.