TAMPA, Fla. (AP) - Tampa Bay's struggling defense will be without middle linebacker Kwon Alexander for the remainder of the season.
The fourth-year pro was injured during the first half of Sunday's 26-23 overtime victory over the Cleveland Browns.
A MRI performed Monday confirmed that the 24-year-old, a fourth-round draft pick in 2015, has a torn anterior cruciate ligament in his left knee.
"It's unfortunate," coach Dirk Koetter said. "Kwon was playing so well, and was the heart and soul of our defense."
Koetter said backup linebacker Jack Cichy also suffered a season-ending knee injury against Cleveland and will miss the remainder of the year.
"Our locker room at halftime was extremely emotional," Koetter said. "Kwon came out of the training room right about the time we were getting ready to go back on the field. It was emotional. You could tell guys really care (about him)."
Alexander has started all 46 games he's appeared in during his NFL career. He was a Pro Bowl selection two years ago and was having one of his best games of the season when he took an awkward step while rushing the passer and tumbled to the ground in the final minute of the second quarter.
He walked off the field and to the locker room without help, but he did not play the second half.
"Guys like Kwon mean everything to this team, and I have empathy for him," quarterback Jameis Winston said.
"Before we left out there for halftime, he was like: 'Never take anything for granted.' He's so right," Winston added. "We see the passion he plays with. We see the heart he puts in the locker room. ... We're going to miss him, and I know he is going to make an amazing comeback."
Losing Alexander and Cichy will severely test a unit that was criticized for its play during a three-game losing streak that followed a 2-0 start.
Cornerback Vernon Hargreves III and safety Chris Conte were placed on injured reserve in September. First-round draft pick Vita Vea missed most of training camp and the start of the season with a calf problem, and four other players - tackles Gerald McCoy and Beau Allen, end Vinny Curry and cornerback Brent Grimes - have missed at least one start because of injuries.
With Tampa Bay sitting at or near the bottom of the league in several key categories, including points allowed, defensive coordinator Mike Smith was fired last week and replaced by linebackers coach Mark Duffner.
The defense was sharper in its first game under Duffner, sacking Baker Mayfield five times and yielding a season-low 305 yards to the offensively challenged Browns.
"You've got to have a next-man-up mentality. Kwon is a key piece to this defense," linebacker Lavonte David said, adding that several reserves stepped up and played well while filling in for McCoy, Curry and Alexander against Cleveland.
"Those guys ... filled the void, and that's what you've got to do," David added. "You never know when your number's going to get called, and their numbers were called (Sunday)."
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