DALLAS — Los Angeles Lakers guard Austin Reaves will miss the rest of the regular season with a Grade 2 left oblique muscle injury, the team announced Saturday. A league source told The Athletic that Reaves is expected to miss four to six weeks with the injury.

The injury news comes one day after the Lakers learned Luka Dončić would miss the remainder of the regular season — at least — with a Grade 2 hamstring strain.

Reaves suffered the injury in the first half of the Lakers’ blowout loss to the Oklahoma City Thunder on Thursday when he reached back to tap a loose ball to himself. Immediately after grabbing the rebound, Reaves reached for his left side in pain.

He remained in the game despite appearing uncomfortable. He went back to the locker room minutes later after checking out, only to return in the second quarter. He was taken out of the game in the third quarter shortly after Dončić suffered his hamstring injury.

Reaves had been playing through a number of other injuries, including one to his right wrist.

The Lakers will be without Reaves’ 23.3 points, 5.5 assists and 4.7 rebounds in addition to the 33.5 points, 8.3 assists and 7.7 rebounds they lost with Dončić’s injury.

Reaves is expected to decline the final year of his contract and become an unrestricted free agent this offseason.

LeBron James, at 41 and in his 23rd season, is now the last member standing of the team’s Big Three. The Lakers went 15-2 and put themselves in control of the West’s No. 3 seed in March, partially because James sacrificed and molded his game around Dončić and Reaves.

Now, that changes.

“You got to flip the mindset a little bit,” James said Saturday at practice. “… I think it’s up to all of us — whoever is in the lineup — to pick up our play.

“Pick up our individual play, and make plays together, and figure out ways we can get stops and figure out ways we can get the ball moving from one side to the other side offensively. And then keep the same keys. No turnovers, obviously. Limit teams’ fast-break points. Limit teams’ offensive rebounds. So it’s a lot of keys that we still need to do in order for us to win.”

Before the Lakers knew for certain they’d be without Dončić, Reaves and Marcus Smart (who is still dealing with a sore ankle), Lakers coach JJ Redick said he thought the team had enough playmaking to survive.

“There’s enough that we have in that we can, you know, play through LeBron, play through Luke (Kennard), play through Rui (Hachimura), play through (Deandre Ayton). … And then we’ll just wait and see until Austin and Smart are back. But our mission hasn’t changed,” Redick said Saturday. “We want to go get the 3 seed and we want to win a first-round series. And I know Luka’s gonna do everything he can to get back on the court. We don’t know what this recovery timetable looks like.

“But, you know, our job, the rest of these guys, and my staff, we’re going after the 3 seed, and we’re gonna try to win a playoff series. And we’ll see what happens.”

The Lakers, though, are no longer just waiting on Dončić.