EL SEGUNDO, Calif. — How important is Anthony Davis to the Lakers?

Very, extremely, incredibly — and any other adverb that would summarize his significance while sidelined during the Lakers’ lopsided loss Tuesday to the Phoenix Suns.

The Suns led by 30 in the second quarter and thoroughly dominated a 115-85 Game 5 victory that tilted the first-round playoff series precariously away from the Lakers.

If the defending champions lose to Phoenix on Thursday at Staples Center, their season is over significantly earlier than anyone could have predicted six months ago. Game 7, if there is one, would be Saturday in Phoenix.

The Lakers couldn’t muster nearly enough offense without Davis, who sat out because of a strained groin. He is being called day-to-day by the team but did not play Tuesday after doing some light shooting before the game.

LeBron James was the only Lakers starter to score in double figures, finishing with 24 points and 7 assists. He did not play in the fourth quarter because the Lakers were down 29 when it started.

“We got our ass kicked,” James said afterward. “It’s that simple.”

There were rough numbers for the Lakers beyond the final score. Their starting backcourt of Dennis Schröder and Kentavious Caldwell-Pope did not score a point in 40 combined minutes.

Schröder missed all nine of his attempts — the worst shooting game of his career — and went scoreless for the first time in five years. Caldwell-Pope came into the night with a sprained knee and took only one shot before exiting early.

The second quarter was the Lakers’ undoing. They did not make a basket for the first 7.5 minutes of it and managed only 10 points on the way to a 66-36 halftime deficit.

“We just didn’t show any heart,” said forward Kyle Kuzma, who finished with 15 points. “They did whatever they want offensively, punked us defensively. We got disrespected out there. We’ve got to strap it up [for] Game 6.”

Despite Davis’ absence, the Suns were favored by only 4.5 points. It’s safe to say they covered the spread.

Devin Booker got the Suns going with 18 points in the first quarter and Phoenix’s defense took it from there. Booker finished with 30 points while backup point guard Cameron Payne continued his strong series with 16 points in 19 minutes.

Kuzma knew what the Lakers were missing without Davis.

“Defensively, I think that’s the biggest thing,” Kuzma said. “We all know what he can do offensively but him being that (defensive) anchor for us…We just saw guards all night just walk to the rim. I don’t think that would have been the case if he played a little bit.”

James said he would prepare for Game 6 as if Davis wouldn’t be available. Even if he does suit up, the Lakers face a must-win situation Thursday.

“We have to find that sense of desperation that has not hit this team enough for, like, this season,” forward Markieff Morris said. “Being down 3-2, our back against the wall, last game of the season possibly, would be a good time to show our championship DNA. We’ve just got to fight, man.”