Tiger Woods' former coach Butch Harmon has called comments made about Phil Mickelson by the world number one's caddie Steve Williams "deplorable".

New Zealander Williams made disparaging remarks about Mickelson in a newspaper interview at a charity event in his homeland over the weekend, bringing into the public domain once again the bitter rivalry that exists between the current world number three and Woods.

Harmon, who works with Mickelson after spending a decade closely associated with Woods, has hit out at Williams and is confident his comments do not reflect the opinions of his employer.

"I can't believe he said what he said," said Harmon. "I think it's deplorable that he would say something like that.

"Golf is a game of honour and integrity and that was a very uncalled-for remark and I don't think it's a reflection of how Tiger thinks of Phil Mickelson.

"Until I see Steve and have a conversation with him and find out why he said what he said I don't really understand it. Phil Mickelson is one of the most popular players in the world, every bit as popular as Tiger Woods around the world.

"He's a nice guy, all the guys like Phil so I don't know where Steve was coming from with that comment.

"But personally I would assume he wishes he had never made it and I would love to have heard a recording of the conversation between him and Tiger after it came out in print.

"Having worked with Tiger for 10 years, I can tell you he wouldn't have been very happy with that."

Williams' outburst came soon after Ireland's Padraig Harrington talked publicly about his less than perfect relationship with Ryder Cup team-mate Sergio Garcia, but Harmon does not feel the game is in danger of losing its genteel reputation.

"We really do have one of the purest forms of sport in the world," he said. "It's the only sport in the world where cheating isn't normal, where players call penalties on themselves.

"It's an environment that we all play in and we all enjoy but it is very competitive.

"There's a tremendous amount of money involved in golf these days and there's a tremendous amount of rivalry between the players.

"The interesting thing about this whole Steve Williams stuff is, if you watch these players in the locker room or on the practice tee, they all get along great. It's like one big fraternity.

"Yes, you have egos involved and people are very self-centred but that's also the way the game teaches you. You're out there on your own and that's the way you play.

"But I think competition is what breeds the rivalries. I think the press and the fans read more into the rivalries than the players do. The players just go out and try and play the best they can play and whatever's going to happen is going to happen.

"They all have their own fans, the way the press perceives them tends to create these type of things. I have no idea why Steve Williams said what he said and quite frankly he probably wishes he never had."

Woods earlier admitted he was not happy about Williams' outburst but had "dealt with" the matter.

"I was disappointed to read the comments attributed to Steve Williams about Phil Mickelson, a player that I respect," Woods said in a statement.

"It was inappropriate. The matter has been discussed and dealt with."

Mickelson has also been scathing of Williams, who has served as Woods' caddie since 1999.

"After seeing Steve Williams' comments all I could think of was how lucky I am to have a class act like Bones (Jim MacKay) on my bag and representing me," Mickelson said in a statement.