Boston Celtics point guard Kyrie Irving could be out until May after undergoing a minimally invasive procedure on his left knee on Saturday.

The procedure to remove a tension wire in his surgically repaired left knee is expected to alleviate irritation that has caused him pain for over two weeks.

He is expected to return to basketball activities in three to six weeks.

The regular season ends on April 11 with the first round of the playoffs set to begin April 14. A six-week absence would keep Irving out until May, by which point the playoffs should be entering the second round.

Boston have clinched a spot in the playoffs, sitting in second place in the Eastern Conference, 4.5 games behind the Toronto Raptors and six games ahead of the Cleveland Cavaliers.

If the current Eastern Conference standings were to hold, the Celtics would face the Miami Heat in the opening round.

The procedure comes after reports surfaced this week that Irving, who turned 26 on Friday, was seeking a second opinion because of a lack of progress with the ailing knee. 

The problem initially flared up on March 3 during the Celtics' loss to the Rockets, and Irving has since missed six of the team's eight games.