Rory McIlroy says an attempt to add speed to his swing contributed to his poor showing at this week's Players Championship.
The 2019 winner missed the cut at Sawgrass after finishing on 10 over-par after the second round.
McIlroy admits he tried to make changes after watching Bryson DeChambeau ease to a six-stroke victory at the US Open last autumn.
"I'd be lying if I said it wasn't anything to do with what Bryson did at the US Open. I think a lot of people saw that and were like, if this is the way they're going to set golf courses up in the future, it helps. It really helps.
"The one thing that people don't appreciate is how good Bryson is out of the rough. Not only because of how upright he is but because his short irons are longer than standard, so he can get a little more speed through the rough than us, than other guys.
"And I thought being able to get some more speed is a good thing, and maybe to the detriment of my swing, I got there, but I just need to maybe rein it back in a little bit."
The Northern Irishman says he began his strive to add distance to his long-game in the aftermatch of the US Open.
"Probably the swing issues and where it all stems from, probably October last year. I was doing a little bit of speed training, started getting sucked into that stuff, and my swing got flat, long, and too rotational.
"Obviously I added some speed and I am hitting the ball longer, but what that did to my swing as a whole probably wasn't a good thing, so I'm sort of fighting to get back out of that. That's what I'm frustrated with.
"I felt like I made some good strides. I played well at the Tour Championship, played well at the US Open. I sort of look back at Winged Foot and I look at my swing there, and I would be pretty happy with that again.
"And then after Winged Foot I had a few weeks before we went to the West Coast and I started to try to hit the ball a bit harder, hit a lot of drivers, get a bit more speed, and I felt like that was sort of the infancy of where these swing problems have come from. So it's just a matter of trying to get back out of it."