PGA Tour commissioner Tim Finchem threw a spanner in the works during the WGC-Accenture Matchplay by announcing that the PGA Tour opposes the plan to outlaw the anchored putting stroke.
Finchem argued that the lack of evidence to suggest players had an advantage by using a long putter meant "there is no overriding reason to go down that road."
In his press conference Finchem said: "We hold the USGA in highest regard as a key part of the game of golf. We don't attempt to denigrate that position in any way whatsoever. It's just on this issue, we think if they were to move forward they would be making a mistake."
His statement comes as golf's governing bodies near the end of a 90-day comment period before deciding whether to adopt the rule, which would not take effect until 2016.
In those 90-days Finchem has been meeting with the players, with USGA executive director Mike Davis presenting the rule in a player meeting in San Diego last month. Finchem sent a letter to the USGA and R&A on Friday to state the tour's position.
The USGA and R&A rule announced on November 28th proposed players be prohibited from anchoring the club to their body, the method used for belly putters and broom-handled putters that are pressed against the chest.
The long putter has become a polarising issue in recent years, even though it has been around for the last four decades, after Keegan Bradley, Ernie Els and Webb Simpson all won majors using the technique.
The USGA and R&A said they wanted to ban the anchored stroke because they felt it took too much skill out of the game.
Finchem made clear that the Tour was not directly going against the USGA, but was only responding to its request for comment. Even so, it puts the USGA in a position of going through with the ban or backing down because the PGA Tour opposes it.
The USGA recently issued a statement that it is listening to "many productive conversations across the golf community" on the proposed rule.
"As we consider the various perspectives on anchoring, it has always been our position that Rule 14-1b aims to clarify and preserve the traditional and essential nature of the golf stroke, which has helped to make golf a unique and enjoyable game of skill and challenge," the statement said.
The USGA said it would decide on the proposed rule in the Spring.