Brooks Koepka says his brother is 'on his own now' after Chase looks likely to be relegated from LIV Golf.
He briefly flirted with a 59 when he was 8-under par after 13 holes at Royal Greens Golf & Country Club in King Abdullah Economic City.
But the 33-year-old American had to settle for a 62 which was good enough for a three-shot lead heading into the final round.
"I wasn't even thinking about the 59," Koepka told reporters after his second round. "I was just thinking about playing good golf. I could care less about the number. I've got the lead and that's all that matters. 59 is irrelevant, you just gotta win."
Chase was the first Koepka brother to sign up for the breakaway tour in it's beta-test year. He finished inside the top-25 players in 2022 which earned him the right to compete in the second campaign.
But it has been a poor season for the 29-year-old, who sits in the relegation zone along with Lee Westwood, James Piot, Jed Morgan, Martin Kaymer and Sihwan Kim.
Westwood won't be booted out of the league because he has signed a multi-year contract with LIV.
Chase, though, will have to assess what he wants to do. He was playing mini tour golf before he joined the Saudi-backed circuit.
His brother bought him a Lamborghini in 2022 with LIV money but going forward Brooks said he is 'on his own'.
Brooks Koepka says it's 'disappointing' his PGA Championship victory doesn't count for anything when asked about a LIV Golf bonus.— GolfMagic (@GolfMagic) October 13, 2023
Brooks said: "He got team money last year, so that was the difference. No, it doesn't go into my pocket now. He's doing just fine. He blew his back right tire out, so maybe he can buy a new tire. I know he got it fixed a couple weeks ago, so yeah, he's on his own now."
He added: "I mean, there's nothing I can do. At the end of the day, it's up to him.
"I know he's working hard. I know he's been trying. We've been practicing together quite a bit. Honestly, he's struggling a little bit. I've been there. We've all been there. Every golfer has.
"It's part of it. You look at it, he was playing mini-tour golf 16 months ago.
"I don't think the last year and a half has been too bad for him."
Sergio Garcia and Charles Howell III are two strokes behind Brooks heading into the final round.
The Australian is 10 strokes behind the lead.
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