Interview footage from the golf tournament leaked on to social media today sees Koepka visibly annoyed as DeChambeau walks behind him during a post-round take.
Their feud goes back years with reports of a bust up on a practice green over DeChambeau’s slow play, and a Twitter spat sparked by Koepka’s cover shoot of ESPN Magazine.
This is how the latest instalment of their ongoing fall out went...
What did Bryson DeChambeau say?
Koepka appeared to be infuriated by something off camera as the reporter set up the shot for a pre-recorded post-round interview at the USPGA for the Golf Channel.
Asked about his performance, the 31-year-old said: “I just ball-struck my way around this place. I didn't putt well but I don't think many guys are going to putt well in this wind. It's very tough.
“I don't know what the other guys have said but I found it difficult to read sometimes.”
Just 20 seconds into the take, DeChambeau and a member of his team walk right behind Koepka with the sound of shoe spikes and muttering clearly picked up by the microphone.
Their presence irked the interviewee yet what was said by DeChambeau is not clear, with some Twitter users suggesting he taunted Koepka over his putting performance at Kiawah Island.
“Just gotta start it on the right line,” one Twitter user suggested DeChambeau said.
How did Brooks Koepka respond?
An annoyed Koepka tried to carry on with the interview but cut a frustrated figure by DeChambeau’s actions.
“I f***ing lost my train of my thought hearing that bull****. F***ing christ,” Koepka said.
The reporter then joked: “We're going to enjoy that in the TV compound”, before Koepka replied: “I honestly wouldn't even care.”
Why do Koepka and DeChambeau not get on?
Koepka has reportedly been annoyed by DeChambeau’s notorious slow play for years, with tensions heightening between the two on a practice green at a previous tournament.
“I just don't understand how it takes a minute and 20 seconds, a minute and 15 to hit a golf ball; it's not that hard,” Koepka told the Golf Monthly podcast in 2019.
DeChambeau, a university physics major, has taken a scientific approach to golf using his education, which has seen him use clubs with the same length of shaft.
He has also transformed his physical appearance, adding three stones of muscle during the first Covid lockdown, to become the longest hitter in the field.
DeChambeau has taken aim at Koepka’s physique in the past after the latter appeared naked on the front cover of ESPN Magazine’s ‘The Body Issue’.
“I don't know if his genetics even make him look good, to be honest,” said DeChambeau. “I mean, the Body Issue, he didn't have any abs, I can tell you that. I've got some abs.”
Koepka then took a picture on Twitter of his four major trophies, with the caption: “You were right @b_dechambeau I am 2 short of a 6 pack!”
Dechambeau hadn’t won a major at this stage and came before his 2020 US Open success.