According to Charania, the injury occurred in Game 2 on Thursday. Lillard has averaged 20.3 points and 7.3 assists in the series, though he's shooting just 32.9 percent from the field.
In Game 3 on Saturday, Lillard hit just five of his 18 shots, scoring 19 points while registering six assists, six rebounds and two steals as the Golden State Warriors took a 3-0 series lead with a 110-99 win.
Injuries haven't been much of a problem for the point guard in his career, as he's never missed more than 10 games in a season. He played all 82 games in each of his first three years before averaging around 76 games over the past four years.
Although he was slowed by calf, hamstring and ankle injuries during the 2017-18 season, he still came through with 26.9 points and 6.6 assists per game. Not only did he earn his third All-Star selection last season, but he also finished fourth in MVP voting behind James Harden, LeBron James and Anthony Davis.
Lillard's injury is an obvious concern for the Blazers, who are down 0-3 to the Kevin Durant-less Warriors. It appears Lillard will continue playing through the injury, with Game 4 set for Monday at 9 p.m. ET in Portland.