SAN DIEGO: Already missing Tiger Woods because of a sex scandal, the PGA Tour headed into another mess Friday when a player accused Phil Mickelson of "cheating" for using wedges that are allowed under a legal technicality.

"It's cheating, and I'm appalled Phil has put it in play," Scott McCarron said in Friday's edition of The San Francisco Chronicle.

Mickelson is among at least four players at Torrey Pines using a Ping-Eye 2 wedge that was made 20 years ago and has square grooves. Such grooves now are banned on the PGA Tour because of a new USGA regulation this year that irons have V-shaped grooves.

The square-groove Ping wedges remain legal, however, because of a lawsuit that Ping filed against the USGA that was settled in 1990. Under the settlement, any Ping-Eye 2 made before April 1, 1990, remains approved because it takes precedence over any rule change.

McCarron's comments resonated across Torrey Pines because "cheating" is considered one of the dirtiest accusations in a sport that prides itself on honesty and players calling penalties on themselves.

Mickelson refused to be drawn into a debate with McCarron over his choice of words, but rather criticized the USGA for adopting such a rule change in the first place, especially knowing that this loophole might cause problems.

"It's a terrible rule. To change something that has this kind of loophole is nuts," Mickelson said. "But it's not up to me or any other player to interpret what the rule is or the spirit of the rule. I understand black and white. And I think that myself or any other player is allowed to play those clubs because they're approved — end of story."

The dispute comes at a time when the PGA Tour is trying to return its focus to golf after a troublesome two months involving Woods, its biggest star who is taking an indefinite break while dealing with the fallout from his extramarital affairs. The Farmers Insurance Open, the 2010 debut for Mickelson, is the first tournament on network television.

McCarron, a three-time winner who missed the cut Friday, said he was not singling out Mickelson for cheating, but rather every player who chose to use the old Ping wedges because he felt it violated the spirit of the new rule.

He was asked if he regretted using that choice of words.

"That anybody using that wedge is cheating? I still feel strongly about it," McCarron said. "Anyone using that wedge, I feel, is behind the rules, even though we have a rule that because of a lawsuit says it's OK."

Told that the Ping club is approved for play, McCarron replied, "It was approved because of why? Because of a lawsuit years ago? I don't think that's in the spirit of the rules. Golf is a gentleman's game. I don't think anyone should be using it."

Mickelson said he did not agree with how McCarron chose to vent his frustration. The world's No. 2 player said he was more bothered by a rules change that so few players embraced, and that the USGA and PGA Tour should have seen this controversy coming.

"I don't appreciate the governing bodies putting me or any other player in this position, calling into question our integrity over a rule that they made, a club that they approved," Mickelson said. "Don't put the blame on a player. Put the blame on the governing body."

Ryuji Imada, tied for the 36-hole lead at the Farmers Insurance Open, didn't agree that players were able to use a Ping wedge with square grooves, although he said, "I don't consider it cheating."

"The rules are the rules, and if it's allowed by the rules of golf, sure, you can use it," Imada said. "But I don't agree with it. If everybody else is having to play the V-grooves, I think everyone should have to play the conforming grooves."

McCarron, recently appointed to the 16-member Players Advisory Council that deals with competition issues, said it likely would be brought up at a meeting next week.

The PGA Tour said in a statement Friday evening that it was aware some players might use the old Ping wedges with square grooves.

"We will monitor this situation as we move forward, and under our tournament regulations, we do have the ability to make a local rule which would not allow the clubs," the statement said. "There's been no decision at this time."

PGA Tour spokesman Ty Votaw said it had a different settlement with Ping in 1993 that contained "different conditions," which would allow the tour to ban the Ping clubs.

Square grooves are deeper and typically provide more spin than V-shaped grooves. One reason the USGA chose to ban the square grooves was to put a greater premium on accuracy off the tee. It felt too many players were able to spin the ball out of the rough, making it easier to stick the ball closer to the pin.

Still to be determined is whether wedges at least 20 years old can produce the same spin as modern clubs with V-grooves. Further complicating the issue is that not every player has access to the clubs made so long ago. Ping no longer manufactures the club, but because of serial numbers, it can confirm to players whether Ping wedges they find in garages or on eBay were made before 1990.

John Daly was the first to use the Ping wedge two weeks ago at the Sony Open, as did Dean Wilson. More players followed, and Hunter Mahan's caddie found a copper-colored Ping wedge for him to use this week.

Robert Allenby is among those who think using the wedges violates the intention of the new rule. However, he chose his words differently from McCarron when asked about it Thursday.

"I think cheating is not the right word," Allenby said. "But it's definitely an advantage. There's only a certain amount of people that can find them, and I just think it's not right if you're using them."

Mickelson made no apologies. He said he submitted wedges to the USGA that met the new requirements yet were not approved, but there was a wedge the USGA approved — Ping — that did not meet the new rules. He also said testing procedures are different in the United States and overseas, adding to the frustration.

"This whole groove thing has turned into a debacle," Mickelson said.

Mickelson said he wasn't sure if he would continue to play his Ping wedge, saying he didn't find much difference in spin from that and the regulation grooves in his other wedges.

"There's a good chance I'll switch back, but not for the reason that I feel like I've been doing something wrong," Mickelson said. "I think that any player using these clubs that are approved under the rules of golf are fine."