The Panthers captain left in the second period of a 4-3 overtime loss to the San Jose Sharks at SAP Center in San Jose on Thursday.
Barkov went down awkwardly while battling for the puck in the right corner during a power play at 8:07. After getting up, he immediately asked for the Zamboni doors to be opened and threw his gloves down while walking to the locker room.
The 31-year-old forward was playing in just his second game this season after missing all of 2025-26 because of a right knee injury he sustained on the first day of that season's training camp. He had surgery the day after the injury to repair his MCL and ACL.
A player on LTIR is required to miss at least 10 games and 24 days.
Panthers coach Paul Maurice on Thursday said it was "not related to his injury last year at all."
Although Barkov was not able to play for the Panthers last season, he did play for Finland at the 2026 IIHF World Championship in Switzerland in May. He served as captain and had 11 points (three goals, eight assists) in 10 games for the Finns, who won the gold medal.
Prior to this season, Barkov said he had no concerns about his right knee.
"I have a better feeling going toward this camp knowing that I played some hockey, meaningful hockey, and felt good there," Barkov said in September. "Especially the more we played, the better I felt. I was really happy about that."
Barkov played 20:32 in the Panthers' season opener on Tuesday, a 1-0 overtime win against the Carolina Hurricanes.
Selected by Florida with the No. 2 pick in the 2013 NHL Draft, Barkov has 782 points (286 goals, 496 assists) in 806 regular-season games. He also has 81 points (25 goals, 56 assists) in 94 Stanley Cup Playoff games, captaining Florida to back-to-back championships in 2024 and 2025.
He is a three-time winner of the Selke Trophy as the best defensive forward in the NHL (2020-21, 2023-24, 2024-25) and also won the Lady Byng Trophy for sportsmanship and gentlemanly play in 2018-19.
The Panthers visit the Anaheim Ducks on Sunday (8 p.m. ET; Prime Video, SCRIPPS, KCOP-13, TVAS).
