Jordan Spieth's struggles on the course have been well-documented since the former No. 1 player in the world began his steep decline to No. 86.
Spieth - who hasn't won since the 2017 Open Championship - has gone from ranking No. 2 in strokes gained: tee to green in 2017 to finishing 90th in that category last season.
Spieth attributes his lackluster performances to one thing: poor swing mechanics.
"It's been a difficult process, to be honest," Spieth said about refining his old swing during an interview on SiriusXM PGA Tour Radio.
He added: "It seems like something (that's) so simple, but when you hit tens of thousands of golf balls kind of the wrong way, it takes about that many to get stuff back, so, it will be a work in progress."
The three-time major winner believes his increased flexibility and mobility over the past few years have been great for generating power, but he said other areas of his game have been negatively impacted because of it "on accident."
"What I didn't realize I did so well for a number of years is being able to swing (the club) in front of my body, pretty much taking it back and through," Spieth explained.
"It just kind of gradually started getting more and more behind me, and then all of a sudden I found myself late into the ball. From there, you just can't play consistent golf, you're relying too much on your hands at impact. It just becomes a significant challenge through the bag, and obviously, as you go up the bag, you're one or two degrees off becomes way more widespread."
Spieth continues to work with longtime swing coach Cam McCormick. A recent report indicated he also visited with renowned instructor Butch Harmon during the offseason.
Spieth has yet to make his 2021 debut.