Thompson had the knee surgically repaired in July 2019 after tearing his ACL in Game 6 of the NBA Finals that year.
"It's nothing serious," Warriors coach Steve Kerr said. "It's just part of cautiousness."
According to Kerr, the original plan was to play Thompson. But during the team's walk-through, Rick Celebrini, the Warriors' director of sports medicine, informed Kerr that Thompson was feeling some discomfort in the left knee and should be held out.
Thompson is considered day-to-day.