LOS ANGELES — Celtics coach Brad Stevens had spoken almost cryptically about forward Jared Sullinger’s foot injury in recent days, and it turns out the prognosis is grim.
After returning to Boston for further evaluation, it was revealed that Sullinger’s injured left foot, initially thought to be a stress reaction, is actually a metatarsal stress fracture. Sullinger, the Celtics’ leading scorer and rebounder, will miss the remainder of the season.
He is not expected to need surgery, but Stevens said he will be in a protective walking boot for about six weeks.
“It’s obviously however many weeks we have in the regular season, plus some,” Stevens said. “You’re talking about a significant thing that he needs a full recovery from.”
Sullinger began to experience discomfort in his foot during Boston’s Feb. 11 win over the Atlanta Hawks. When the team reunited after the All-Star break on Wednesday, Sullinger removed himself from practice because the pain had worsened.
“It [stinks],” Sullinger said Thursday. “It [stinks], honestly, especially with the type of push we’re trying to make.”
Dr. Tony Wanich, an assistant professor of orthopedics at Montefiore Medical Center in New York, said in a telephone interview that injuries such as Sullinger’s are fairly common in sports that require constant running and jumping.
Wanich said stress fractures are a result of overuse, not a single, traumatic event. He said they typically take about six weeks to heal, but recovery times vary.
“The tricky thing with stress fractures is they can sometimes take longer to heal than regular fractures,” Wanich said.
“When you have a regular fracture, you have all this inflammation, and that stimulates the body to heal the bone. The stress fracture is a slower process because there’s not enough trauma to jump-start the system.”
Wanich said it is unlikely that Sullinger’s injury was caused by his 260-pound frame.
“Bones actually are able to adapt and basically get stronger to support your weight,” he said. “Weight can be a factor, but the more important thing to look at would be to make sure there’s not a slight misalignment in the foot.”
Wanich said stress fractures of the foot rarely require surgery, but if the bone is not healing properly after six weeks, surgery sometimes becomes an option. When Sullinger is able to ramp up his rehabilitation, it likely will require a lot of time in a swimming pool.
This is the second time in Sullinger’s three-year career that he has suffered a season-ending injury. He hurt his back during his rookie year and missed the final 37 games.
Sullinger’s absence will be a huge blow to Boston’s postseason hopes. The team entered Sunday night’s game against the Los Angeles Lakers just 1½ games behind Brooklyn for the Eastern Conference’s final playoff spot, and now it must find a way to overcome one more obstacle in a season that has been full of them.
“It’s a big loss for our team,” guard Avery Bradley said. “Obviously, Jared brings a lot to our team and everyone’s been really disappointed. But at the same time, everyone wants the best for him, which is him getting healthy so he can get back out there with us.”
The Celtics were already thin in the interior; 7-footer Kelly Olynyk has been sidelined since spraining his ankle Jan. 22. Olynyk has been participating in light drills, and the Celtics are hopeful he will return soon.
“We’ve just got to find a way,” said forward Tyler Zeller, who has replaced Sullinger in the starting lineup. “Hopefully we can get Kelly back soon, the new guys, be able to rotate them in. Really, we’ve just got to put the pieces together and find a way.”
Six-foot-10-inch forwards Jonas Jerebko and Luigi Datome, who were acquired from the Detroit Pistons in a trade for Tayshaun Prince on Thursday, figure to have increased roles.
Jerebko averaged 5.3 points in 15.3 minutes per game with Detroit. Datome has played just 17 total minutes this year.
“They’ve got a few injuries right now,” Jerebko said of the Celtics, “and I’m hoping to fill that spot and help the team win.”
Adam Himmelsbach can be reached at adam.himmelsbach@ globe.com. Follow him on Twitter @adamhimmelsbach