Phil Mickelson continues to pull no punches.

Shortly after golf’s governing bodies announced a new model local rule that would give professional tours and elite amateur competitions the option to cap maximum driver-shaft lengths at 46 inches, Mickelson took to Twitter to express his disdain.

“Stupid is as stupid does,” Mickelson tweeted. “Really though, are the amateurs trying their best to govern the professional game the stupid ones? Or the professionals for letting them?”

Mickelson, of course, has used social media to vent on this subject before. Before his second round of the BMW Championship in August, he alerted his Twitter followers that the USGA and R&A were on the verge of announcing the shaft rule, a move that he called “pathetic” while accusing the governing bodies of trying to make the game “less fun.” A week later, he released a video diving deeper into the matter, comparing shaft restrictions to the square-groove ban in 2010 and proposing that the USGA and R&A instead get rid of the perimeter-weighted golf ball.

"It's just an idea to start addressing the real issue,” Mickelson said, “and not have all these other issues that are taking a lot of the fun away from the game and not really addressing the problem.”

The USGA declined to respond to Mickelson’s earlier comments, but after Tuesday’s news was announced, Thomas Pagel, the USGA’s senior managing director of governance, appeared on Golf Channel’s “Golf Today” to answer questions, including several that Mickelson had previously posed.

Pagel explained that the model local rule, MLR G-10, not only wouldn’t affect recreational golfers, as it applies to only the game’s highest levels, but it would have minimal impact on the pros; Pagel cited data that determined that just 3% of professional golfers use or have used driver shafts longer than 46 inches (Mickelson, Bryson DeChambeau and Dylan Frittelli are the notable players).

Pagel added that this local rule wouldn’t be the only step taken to stop the cycle of increased hitting distance. When asked about smaller driver heads and ball rollbacks, Pagel confirmed that the USGA was still “actively engaged” in discussions with the golf community on those issues.

“Again, this is not a solution, it’s not the solution to Distance Insights,” Pagel said. “We remain committed to the fact that we see distance long-term creating challenge for the game and we want to identify solutions so that the game can be just as healthy as it is today 20, 30, 50 years from now. … Let’s be proactive, and if we know that golfers have the ability to gain additional yardage by going to a longer club over time, let’s just cap it now.”

The LPGA will put the local rule into practice "sometime after the 2021 season," according to Golfweek's Beth Ann Nichols.  The PGA Tour said in a statement Tuesday afternoon that it would adopt the local rule when it first goes into effect on Jan. 1 of next year. While Mickelson is not competing in this week’s CJ Cup in Las Vegas, other players were asked about the USGA’s decision during Tuesday's press conferences at The Summit Club.

“I don't really agree with it,” Justin Thomas said. “I feel like there's a lot of other things, you know, like the arm-bar putter that they should be approaching as opposed to the length of driver. I think the fact that you see only a few people using a long driver speaks for itself, that it's not really that big of an advantage. It's a lot harder to hit it straight. In terms of do I think it makes the game of golf and growing the game better? No, I don't at all, but they seem to have their kind of mind around that for a while now. … If there's guys out here that want to have a chance to put it in play with a 47-, 48-inch driver, then power to them. I had that opportunity; I just chose not to.”

Collin Morikawa and Jason Kokrak seemed rather unconcerned about the rule's potential impact, speaking to the scarcity of driver shafts longer than 46 inches on Tour.

“It's not going to change my driver specs, I'll tell you that, and I don't think it's going to change many other guys' driver specs,” Morikawa said. “Is that the answer to hitting it shorter? No. You know, I think yeah, if you have a long drive and you see what Bryson did, you see what long drive guys do, they have a longer driver, right, and they're able to hit it farther, but can you maintain that on the golf course? Hasn't been done yet. Not saying it won't be done, but you know like if a guy wants a 47-inch driver, I think they should let them because why not?”

Added Kokrak: "It doesn't affect me, so I don't have to worry about it."

The players are right in those assessments: Are 48-inch driver shafts really a major problem in the distance-gain conversation? No. But as Pagel said in his interview, the governing bodies were being “proactive” with this rule, whereas in the past, technological advancements in equipment have produced rising distance gains that are just now being addressed.

If driver heads and the ball are next up for distance mitigation, and the length of driver shafts hadn’t been restricted, would shafts become the new avenue for increasing distance? And though it’s harder to hit a 48-inch driver straight, how long before technology makes it easier? Those are likely questions that the governing bodies have considered.

So, while Mickelson and Co. may disagree, it appears that the USGA and R&A have already made their final decision on shafts.

And with that, we’ll go to Lee Westwood, who had the perfect response to Mickelson’s latest tweet.

As Westwood replied, “What difference does a couple of inches make!?”