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Golden State Warriors head coach Steve Kerr will not coach Monday's Game 4 against the Portland Trail Blazers and could be out for significantly more time.

Marc Stein of ESPN noted Kerr announced Sunday he won't coach Monday’s contest, while Chris Haynes of ESPN reported the coach said he may not return during the entire postseason if his back doesn't get better.

According to Ethan Strauss of ESPN, Kerr is consulting doctors about his back issues. Adrian Wojnarowski of The Vertical reported Kerr believes he can take part in practice and film sessions but is unable to handle the challenges of game nights.

Kerr missed Saturday's Game 3 victory with an illness, and Stein reported the cause was unknown Sunday morning. Stein also cited sources who said the Warriors hadn't yet determined at the time whether Kerr's symptoms were related to the complications he suffered during the last two seasons following back surgery in July 2015.

"I can tell you, if you have a back problem, stay away from surgery," Kerr said, per Connor Letourneau of the San Francisco Chronicle. "I can say that from the bottom of my heart."

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Kerr missed the first 43 games of the 2015-16 campaign with those complications (headaches and nausea, among others), and now-Los Angeles Lakers head coach Luke Walton guided the team in his absence.

“I don’t know if he can do this very much longer,” an unnamed "NBA associate close to Kerr" told Wojnarowski. “He hasn’t enjoyed this one bit. Even if we haven’t talked in a bit, I can see the pain on his face.”

Lead assistant coach Mike Brown coached Golden State in Saturday's contest and led it to a commanding 3-0 series lead over the Trail Blazers. Brown was a head coach for the Cleveland Cavaliers and Lakers for eight seasons.

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