"Yeah," Koepka said with a nod when asked if people made too much of his friendship with DJ, according to Golf.com's Dylan Dethier. "We worked out for - I worked with Joey for two years. Yeah, I mean, I don't know."
Koepka and Johnson trained together with golf fitness coach Joey Diovisalvi earlier in their careers. The two golfers were connected in television segments, magazine covers, and press conferences.
Brooks even called DJ one of his "best friends" after the 2018 Ryder Cup, but his tone on their relationship has changed.
"I don’t know what you guys - you guys make your own stories, so I have no idea what you all do," he said. "I think even the Jordan (Spieth) and Justin (Thomas) thing gets blown out too much. I think you guys overplay - you guys overplay a lot of things."
Koepka threw shade at Johnson ahead of the PGA Championship's final round, in which Brooks trailed Dustin by two strokes entering Sunday.
"A lot of the guys on the leaderboard, I don't think have won. I guess DJ's only won one, but I don't know the other guys that are up there," Koepka said. "A lot of experience, I guess, is what I can bring to it. Know that I've been in this position quite a few times over the last couple years."
Koepka told Golfweek's Eamon Lynch on Wednesday he regretted the part of his comments that failed to acknowledge the players on the leaderboard without major titles, but he didn't plan on reaching out to any of them for an apology, including DJ.
"That’s not something I’m planning on doing," he said.