On Friday, outspoken Englishman Eddie Pepperell took to his his Twitter account to call out DeChambeau after the American had taken more than two minutes to line up a putt once it was his turn to play at the eighth hole.
After DeChambeau shot an even-par 71 to finish the third round at six-under-par on Saturday, he addressed media to refute his reputation as a slow player.
"It has just got out of hand", Koepka said.
United States golfer Bryson DeChambeau hit back on Saturday at critics who took to social media to complain about his painfully slow pace of play. "It's like I told him, I've mentioned his name once, and that's it".
Rightly, pressure is growing on the PGA Tour to take action and impose penalty strokes to punish slow play.
Another showed DeChambeau taking more than two minutes to hit a simple five-foot putt. On Friday, video surfaced showing DeChambeau taking more than two minutes to hit a 70-yard pitch shot.
An official will inform the group if they're being timed - players have 40 seconds to play each shot, or 50 seconds if they're first to play.
There is not now a policy to assess penalties or fines when players' groups are in position, but the TOUR could consider adding one.
The TOUR's current pace-of-play policy only addresses players whose groups have fallen out of position.
There are many factors to consider when deciding an appropriate amount of time to play a shot, Dennis said. "Some of these are things we can influence, and some are not".
Under the TOUR's current pace-of-play policy, players are "on the clock" when their group falls out of position. The first bad time results in a warning, while a second bad time in the same round is a one-stroke penalty.
Players are fined for a second bad time in a season, and each bad time thereafter.
Why DeChambeau turned his attention to Koepka, who hasn't called him out personally this week, on the practice green remains unknown. "I appreciate what Brooks did". There was one instance he said [from Dubai] and he said, 'Yeah, I said something about that, but it was in general and got blown out of proportion'.
DeChambeau, who is known for an idiosyncratic approach that includes using clubs all cut to the same length and a mathematical approach to reading greens, said he felt he was "somehow being singled out". "We had a great conversation and I have a new level of respect for him". That's what it looked, or that's what it said in the book, but it didn't look like that to my eyes.
"The issue is it's in the rule book, " Koepka said. It's just like hitting it in the water, I gotta take a penalty stroke except I don't want to take a penalty stroke. I'll be the guinea pig. That's just what's going to happen every once in a while. "I'm the one who is talking about it probably the most out of any player".