Irving to have surgery on sore knee

The Celtics say All-Star point guard Kyrie Irving is set to have surgery today to alleviate pain in his left knee.

Irving has been out since March 11, missing the last four games. There is no timetable for his return from the “minimally invasive” procedure.

Celtics coach Brad Stevens was asked before Boston’s game in Portland on Friday night the ramifications of Irving’s surgery.

“I don’t know yet,” Stevens said. “He’s going to have it tomorrow and we’ll know more about timelines after that.”

The knee is the same one that Irving injured in the 2015 NBA finals that required surgery.

Irving is averaging 24.4 points, 5.1 assists and 3.8 rebounds per game. Friday was his 26th birthday.

He is one of several key sidelined players for Boston, which was at Portland on Friday. He joins Jaylen Brown (concussion protocol), Marcus Smart (thumb surgery), Daniel Theis (knee surgery, out for season) and Gordon Hayward (ankle surgery rehab).

Stevens said the team will focus on its strengths in light on the injuries.

“Do what you do best. That’s it,” he said. “Everybody’s got something they do well otherwise they wouldn’t be in the NBA. Don’t try to be something you’re not, don’t try to make up for Kyrie’s absence, or Smart’s absence, or Tyson’s absence by trying to do what they do. Just do you and just be good at it, be reliable at it. That’s all we’re going to ask.”