SAN DIEGO: Ping chairman John Solheim reminded the PGA Tour on Monday that it cannot make a separate rule to ban Ping Eye2 wedges, the 20-year-old clubs that led Scott McCarron to claim Phil Mickelson is "cheating" by using them.

Hours after McCarron said he would "not be silenced" over the grooves controversy, the PGA Tour's situation became a little more muddled with Solheim's gentle reminder.

Mickelson was among at least four players at Torrey Pines who used the Ping wedges, which have square grooves.

The USGA has a new regulation this year that shrinks the volume and softens the edges of the grooves. However, the Ping wedges made before April 1, 1990, are approved for competition because of a 1990 settlement from Ping's lawsuit against the USGA.

The PGA Tour said in a statement over the weekend that it would monitor the situation, noting it could adopt a "local rule" for tournaments that would ban the Ping wedges.

Solheim, however, said under the 1993 agreement with the PGA Tour, the tour could not adopt a separate rule if it differed from the USGA.

"The recent statement from the PGA Tour and several PGA Tour players that they could invoked a 'local rule' required us to remind the PGA Tour of the terms of the agreement," Solheim said in a statement.

Then, the chairman and CEO of Ping appeared to leave room for a compromise.

"While I fully expect the PGA Tour to honor this agreement, I'm willing to discuss a workable solution to this matter that would benefit the game and respect the role innovation has played over the long history of golf," Solheim said.

Solheim is the son of Ping founder Karsten Solheim, one of golf's foremost innovators who spent millions battling the USGA and PGA Tour over the square grooves in its popular Ping Eye2 model.

PGA Tour spokesman Ty Votaw declined comment, noting commissioner Tim Finchem would have a press conference Tuesday in Los Angeles after a players meeting.

McCarron and Mickelson, meanwhile, struck no conciliatory tones.

McCarron, who has won three times in his 16-year career, issued a statement Monday in which he wanted to clarify that while he believes "it's cheating" for Mickelson or anyone else to use the Ping wedges, "I never called Phil Mickelson a cheater."

"That being said, I want my fans, sponsors and most importantly, my fellow players, to know that I will not be silenced and I will continue my efforts to get the groove issue resolved," McCarron said.

Mickelson, the world's No. 2 player, had said over the weekend he felt "publicly slandered" and hinted at legal action if the PGA Tour does not discipline McCarron for his choice of words.

"Again, everybody has their opinions and so forth, and it's healthy to talk about it," Mickelson said Saturday. "But when you cross that line and slander someone publicly, that's when the tour needs to step in — or someone else."

John Daly and Dean Wilson were the first players to use the Ping wedges this year, at the Sony Open in Hawaii. Others who have had the Ping wedge in play include Hunter Mahan, whose caddie found a copper wedge with square grooves.

An industry official said three-time major winner Padraig Harrington showed up at Riviera on Monday with two sets of Ping wedges, including one set that was made before 1990 and would be approved for play. The official spoke on condition of anonymity because he was not authorized to speak on Harrington's behalf.

Mickelson did not say if he would continue to play the wedge, although he made it clear at Torrey Pines the decision would not be based on what other players think.

Sports Illustrated reported on its Web site Monday that Randy Peterson, Callaway Golf's director of fitting and instruction, said Mickelson's Ping wedge imparted as much as 25 percent more spin than any of the Callaway wedges with new grooves.

McCarron directed some of his frustration at the USGA and the PGA Tour for knowing the potential for this controversy before it blew up on them last week at Torrey Pines. He said the focus should shift from a small number of players using the Ping Eye2 wedges to the majority of players "who chose to do the right thing."

"I am still appalled by the fact that any player would make the choice to put this controversial wedge in play, and I stand by my previous comments," he said.

Solheim said the controversy did not catch Ping by surprise. He said when the USGA proposed its new groove regulation two years ago, Ping reminded officials of the 1990 settlement. He said he advised the USGA and PGA Tour in a letter dated July 31, 2007, that "what is happening on the PGA Tour today was very much a possibility."