Report: 49ers' LB Kwon Alexander Out for the Season With Torn Pectoral

Adam Schefter of ESPN reports that 49ers' standout linebacker Kwon Alexander will miss the remainder of the season with a torn pectoral muscle.

This is now the second major injury for Alexander in the last three years. When speaking with reporters this morning on a conference call, head coach Kyle Shanahan was very nervous about the pending MRI results for Alexander. The loss of Alexander is a huge blow to the defense.

He was playing at Pro Bowl level and established himself as one of the leaders on the defense. Alexander's impact was felt most in the passing game with his biggest strength being in coverage. Alexander allowed the second-lowest passer rating (58.5) among linebackers into his coverage via Pro Football Focus.

The pairing of him and Fred Warner helped solidified the middle of the field. Now that Alexander is out for the season, rookie linebacker Dre Greenlaw will take the reigns as the starter next to Warner. Greenlaw has been noted as the fastest linebacker on the roster, so he may be sufficient in coverage.

The learning curve for the rookie is about to become expedited. Trying to fill the shoes left by Alexander will be no easy feat. Expect the 49ers to also look to Azeez Al-Shaair for contributions as well.

Defensive Coordinator Robert Saleh will need to make the proper adjustments for the loss of Alexander, especially after the gashing his defense received on Thursday night. This defense is still a vaunted one, but the loss of Alexander cannot be overlooked.