Wentworth - Ernie Els has predicted a legal battle over the ban on anchoring putters set to come into force in 2016 and admitted he would not have won last year's British Open without a long putter.
Els' South African compatriot Tim Clark - who has been using an anchored putting stroke since turning professional in 1998 has already vowed to look into the legality of the ban.
Four of the last six major winners, including Els who won his fourth at Royal Lytham & St Annes last year, have used the controversial method.
Adam Scott won this year's US Masters whilst Keegan Bradley and Webb Simpson have also won their first majors using long clubs.
Els has already been practising with a short putter in preparation for the ban which was announced by the R&A and United States Golf Association on Tuesday but has forecast legal wrangling to come although the PGA Tour in America has yet to reveal where it stands on the issue.
Speaking to reporters at Wentworth ahead of Thursday's start to the PGA Championship Els said: "It is a real issue for some players.
"I think you are going to have some guys who go that way - it is a huge change and some guys are probably going to take some action.
"I have been using this putter for over a year. I have won a major with it. It is a huge issue.
"This is a guy's livelihood you are talking about; a guy having problems on the greens or a guy who is used to playing with the long putter, taking that away from him now is a huge issue.
"It is going to take time for guys to get back into competitive form with a different method of playing the game. It is only natural."
Asked if he would have triumphed in last year's British Open without using a belly putter Els added: "I don't think so. I have thought about it and I was in such a state on the greens but I am a lot better now.
"It was more of a psychological thing for me. I don't think I could have won the Open with a shorter putter."
The PGA Tour could yet allow anchoring of putters during its own events but is waiting to consult with its members before acting.
Clark told USA Today: "We're not going to roll over and just accept this. We will look into all options. We have been put into a position where we have to fight for our livelihoods.
"We will do what we need to do to get a fair result. We certainly have legal standing."
Els added: "I don't want to speak for the US Tour but they are probably going to have to play ball somehow."