Kyrie Irving will seek a second opinion on his sore left knee, according to Yahoo! Sports' Shams Charania.

According to Charania, Irving will get a second opinion after showing a "lack of progress."

Irving has not played since March 11, when the injury forced him to sit out the second half of a 99-97 loss to the Indiana Pacers.

Irving, according to multiple reports, will eventually need surgery.

His problems with his knee date back to the 2015 NBA Finals, when he broke his kneecap and was forced to sit out the remainder of the series.

If Irving can't get healthy, it would be a major blow to the Celtics' ability to make a deep run in the playoffs, which begin April 14.