Boston Celtics star guard Kyrie Irving will undergo a “minimally invasive procedure” on his left knee, the team announced on Friday.

The surgery, which will take place on Saturday, is meant to alleviate the knee soreness that has kept Irving sidelined for most of March.

No timetable for Irving’s return has been given, with the Celtics saying “further information will be provided following tomorrow’s procedure”.

Irving has missed Boston’s past four games and sat out a fifth against Chicago on March 5. He was also shut down for the second half of the contest with Indiana on March 11.

Though an MRI last week came back negative, the knee hasn’t shown enough progress for Irving to get back on the court.

Irving’s left knee is the same one he had surgery on to repair a fractured kneecap in 2015.

It’s unclear whether Irving will be able to play again this season, but the Celtics’ announcement that the procedure is “minimally invasive” comes off as a good sign that it’s not serious enough to rule him out for the rest of the year.

Even if he sits for the final stretch of the regular season, Boston are all but locked into the two seed in the Eastern Conference, sitting 4.5 games behind first-placed Toronto and six games ahead of third-placed Cleveland.

However, with Gordon Hayward, Marcus Smart and Daniel Theis all out with various injuries, the Celtics could choose to play it safe with Irving and shut him down.

The news that Irving will undergo surgery also came on his and Hayward’s shared birthday of March 23.