Tampa was in firm control when Alexander exited the game, and went on to hold a 26-0 lead over the Bears at halftime.
Alexander has quickly emerged as an impact player for the Buccaneers, playing just about every snap each game in the middle of the defense since last season.
The 23-year-old linebacker was a fourth-round pick in the 2015 draft but surpassed virtually all expectations as a rookie. He started 12 games and finished with 93 tackles, three sacks, two interceptions and two forced fumbles in this stretch.
He took an even bigger step in 2016, leading the team and finishing fourth in the NFL with 145 tackles. While the defense as a whole remained inconsistent, Alexander was one of the top performers week in, week out.
This could make an extended absence even worse for the Buccaneers, a squad hoping to take a big leap in 2017.
Although Tampa Bay does have an established defensive playmaker in Lavonte David, the rest of the linebacking corps is relatively inexperienced and difficult to trust. The entire unit will have to step up in order to fill the immense gap left behind with Alexander out, especially backup middle linebacker Adarius Glanton.