That's tough for a 49ers defense that has seen a big boost this season. Much of that was because of Alexander's energetic presence and fast-paced playmaking ability.
The 'Hot Boyzz' linebackers will have to move forward without their veteran teammate.
Alexander didn't sound too discouraged by the injury news on Friday. He tweeted the following out to fans.
Alexander knows what it's like to overcome odds and return better than ever after a season-ending injury. His 2018 campaign with the Tampa Bay Buccaneers was cut short by a torn ACL. The 49ers believed in him so much that, despite the injury, they signed the then-free-agent linebacker to a four-year deal in March.
It looked like a gamble that was paying off until the injury. Alexander was playing at a high level and registered 34 combined tackles, 0.5 sacks, four passes defensed, an interception, and a forced fumble through eight starts this season.
Rookie Dre Greenlaw is expected to start in place of Alexander for the 49ers' remaining games.
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