Photo: Matt Stone/MediaNews Group/Boston Herald

Kemba Walker received a stem cell injection in his knee, and he is going to miss the start of the 2020/21 season, which is set to begin on December 22.

An update on Walker’s availability will be provided in January, as the Celtics announced. Walker’s left knee has been problematic for several years.

In 2016, he underwent surgery to repair a torn meniscus and throughout the 2020 season, he experienced intermittent bouts of soreness that caused him to miss games.

As a result, he was on a minutes-restriction policy during the postseason in Orlando “bubble”. During his first season in Boston, Walker averaged 20.4 points and 4.8 assists per game.

Stem cell injections are a form of therapy that aims to regenerate and repair damaged tissue. The Celtics also announced that Tristan Thompson suffered a minor hamstring injury, and he will miss the first week of the training camp.

Boston’s first pre-season matchup is on December 16 against the Philadelphia 76ers, six days before the official start of the 2020/21 campaign.