Kwon Alexander tore his pec and is out for the season

On a conference call Friday morning, you could hear in San Francisco 49ers head coach Kyle Shanahan’s voice that he knew bad news was on the horizon for Kwon Alexander. The linebacker left Thursday’s game with a chest injury. He was ruled out right away, and some feared that was an indicator of bad news. The optimistic part of the press box figured because the game was in the fourth quarter that may have been the reason.

That was not the reason.

ESPN’s Adam Schefter reported Friday morning that Alexander’s MRI results confirmed that Kwon Alexander tore his pec and is out for the season. That’s a big blow to the 49ers defense, both on and off the field. Alexander was having an amazing season. Alexander allowed the second-lowest passer rating among LBs into his coverage. He helped transform one of the best defenses in the league with his speed, attitude, and energy. You could tell within a few practices back in August that Alexander made a difference.

Now, Dre Greenlaw will move over and play the “Will” linebacker spot. Mark Nzeocha will take over at “Sam” for Greenlaw. Aziz Al-Shaair has a chance to see his role expand as well. He only played three snaps on Thursday, but he may be the next best “pure” linebacker. He’s a rookie, though. So expectations for him and Greenlaw should be tempered. Elijah Lee will likely be promoted from the 49ers practice squad.

Pat’s note: Site decorum is off in this post.