Thompson: Kerr absence a cause for concern.

PORTLAND, Ore. — After scoring the last nine points, including a dagger 3-pointer, Stephen Curry walked off the court with the ball. He had a game-high 34 points as the Warriors took a 3-0 lead in the first-round series against Portland with a 119113 win on the road. But the ball wasn’t for him. It was for Steve Kerr.

“We got his back,” Curry said.

The Warriors biggest worry is not the injury to Kevin Durant. He’s all but ready to take the court again, even though the Warriors held him out for game 3.

His sudden and mysterious absence from the Warriors bench, which came to light at shootaround on Saturday morning, didn’t come with much explanation. Vague descriptions like “illness” and “not feeling well,” is usually a sign something is wrong. In this case, according to sources, it is.

At the worst of this current illness, Kerr was in excruciating pain, according to the sources, and he could barely walk. The worst part, the Warriors don’t yet know what is going.

Kerr has been feeling terrible throughout this series and recently it become unbearable. It is unknown if these issues are even related to his past well-known health problems.

As competitive as Kerr is, we know this: it must be pretty bad if he is missing a playoff game.

Moving forward, the health of Kerr is the one to watch. Not Durant. Not guard Shaun Livingston or forward Matt Barnes, whose second straight missed game leaves the Warriors’ bench shorthanded.

The Warriors are loaded so they can survive in the early rounds. They have the talent, the schemes and the rotations set so Mike Brown can hold the fort.

But over this long championship run, pushing buttons will matter. Fighting against the elements, motivating individual players, managing the roller coaster of emotions. That’s Kerr’s specialty, his responsibility.

Even if the Warriors have veterans with championship experience, removing his presence at this juncture is a significant change.

But Kerr’s health is a sensitive subject for the Warriors. They are acutely aware of how devastating his surgery-gone-wrong has been for his life and how admirably he’s fought through it.

Kerr missed the first 43 games of the 2015-16 season due to complications from back surgery. A spinal fluid leak left him with debilitating headaches and nausea, among other ailments. Even when he returned, he wasn’t 100 percent.

The offseason helped Kerr, as time is the only true cure for his condition. But he still wasn’t fully recovered when the season started. That’s why Brown is here.

The Warriors selected a top assistant with head coaching experience, instead of another bright offensive mind such as Stephen Silas, presumably because of the potential for Kerr to miss time again.

Brown has not only coached a team to the NBA Finals, but he has experience with elite talent — having coached LeBron James and Kobe Bryant. But Brown, unlike Walton, didn’t get a training camp to establish his presence. He doesn’t get regular season games to get comfortable in the big chair.

That was because Kerr survived the regular season. He missed one shootaround but was on the bench for all 82 games. And that’s why him missing a playoff game is a sign of how badly he is hurting.

Kerr had progressed enough to game plan with Brown before tipoff Saturday. But no one knows if he will be around for Game 4. No one knows if he will return for this series.

Knowing Kerr, he could get to a point where he can just tough it out, and then he will downplay it so as to divert the attention. But will the Warriors want him to do that, knowing the truth about how much he is suffering? Will general manager Bob Myers, who at shootaround it appeared had to disappoint Durant and tell him he was sitting out one more game, be OK with his close friend coaching through the excruciating pain? Or will Myers, who is known for his humanistic perspective, care more about making sure Kerr gets healthy?

This situation surrounding Kerr feels a lot like Stephen Curry’s injury last year. The Warriors didn’t know how badly he was hurt, didn’t know when he would be back, didn’t know how he would look when he returned. The entire playoffs were clouded with the uncertainty surrounding Curry and his sprained right knee.

This year, suddenly, the questions surround Kerr. Like Curry, you know he’d give anything to be out there.