Butler scored seven points while playing the entire first quarter, but the Heat ruled him out for the rest of the game.
Miami coach Erik Spoelstra had no postgame update on Butler's condition.
Butler began the night averaging 25.3 points, 6.0 rebounds and 5.5 assists while playing in every game this season for Miami. The five-time All-Star selection was the NBA's 11th-leading scorer.
Butler joined a lengthy injury list for both teams in this showdown between marquee franchises that also met in the 2020 NBA Finals.
The Lakers had just 10 players in uniform without LeBron James (abdominal strain), Rajon Rondo (hamstring) and Austin Reaves (hamstring). Talen Horton-Tucker, Trevor Ariza and former Heat guard Kendrick Nunn have yet to play for Los Angeles this season due to injuries.
The Associated Press contributed to this report.