The 49ers’ loss of Kwon Alexander is a significant blow.
The linebacker, in his first season with the Niners after coming from Tampa Bay, had a terrific first half of the season for his new team, showing athleticism and a far-ranging style that allowed him to be a plus defender against the run and in pass coverage.
But a torn chest muscle suffered in San Francisco’s victory over the Cardinals last week means he’ll lose the rest of the season – and the 49ers will have to hope his backups can pick up the slack.
Alexander in eight games had 34 tackles, an interception, four passes defensed, a forced fumble and a half-sack while starting at weakside linebacker. He gave the 49ers excellent pass coverage, particularly against tight ends.
The plan now is for rookie Dre Greenlaw, who was starting at strongside linebacker, to move to Greenlaw’s position, with veteran Mark Nzeocha and rookie Azeez Al-Shaair getting snaps at strongside linebacker. The 49ers may also promote linebacker Elijah Lee from the practice squad to fill out the group. Lee started five games for the 49ers in 2018.
Alexander had combined with second-year middle linebacker Fred Warner to form a dynamic duo of athletic, speedy linebackers. Head coach Kyle Shanahan said Alexander had taken a leadership role.
“He’s been a great addition for us,” Shanahan told reporters. “It’s going to be a tough loss.”
Greenlaw, a fifth-round pick out of Arkansas, has played well as the strong-side starter, but his responsibilities have been mostly in the base defense, with more limited snaps in pass coverage. In eight games he has been in on 14 tackles, with one for loss, and has a sack. Nzeocha, in his third season with the 49ers, has two tackles, an interception and a pass defensed in limited snaps over eight games. In 2018, he started three games.
Greenlaw gets a few extra days to work into his new position, thanks to the 49ers playing last Thursday and not having to resume play until Monday night, Nov. 11, vs. the Seahawks.
The 8-0 49ers take on the 7-2 Seahawks at Levi’s Stadium. Kickoff is set for 5:15 p.m.