Bryson DeChambeau was accused of "acting like an eight-year-old" by his equipment supplier after the American said his driver "sucks" following his opening round at The Open on Thursday.
The world number six shot a one-over-par 71 to end the day seven shots behind leader Louis Oosthuizen.
"I'm living on a razor's edge, I've told people for a long time," he said.
Cobra, who work with DeChambeau, told Golfweek: "It's really painful when he says something that stupid."
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Speaking after his opening round at Royal St George's, which was played in breezy conditions on the Kent coast, DeChambeau said: "If I can hit it down the middle of the fairway, that's great, but with the driver right now, the driver sucks.
"It's not a good face for me, and we're still trying to figure out how to make it good on the mis-hits."
He said before the championship that he was considering hitting irons off the tee in an attempt to keep his ball out of the thickest rough - and 28% of his tee shots were wayward in his opening round.
In his quest to hit the ball further off the tee, DeChambeau has been tinkering with his clubs for many years and Ben Schomin, tour operations manager for Cobra, says the manufacturer "bends over backwards for him" trying to create the perfect driver.
"He's in a place where he's swinging a 5-degree driver with 200 mph of ball speed," added Schomin, who caddied for DeChambeau two weeks ago after he split with long-time caddie Tim Tucker.
"Everybody is looking for a magic bullet. Well, the magic bullet becomes harder and harder to find the faster you swing and the lower your loft gets."
"He has never really been happy, ever. Like, it's very rare where he's happy [with his driver].
"He didn't really mean to say it that harshly. It's like an eight-year-old that gets mad at you. They might fly off the handle and say, 'I hate you'. But then you go. 'Whoa, no you don't'.
"We know as adults that they really don't mean that."