"I don't see why they don't firm greens up and get the rough longer to bring scores down," McIlroy said Tuesday. "They can make golf courses a lot tougher and turn 20-under winning scores into 12 under."

The USGA and The Royal & Ancient in January introduced rules designed to prevent tour professionals from putting excessive spin on golf balls when playing out of long, rough grass.

The measures have been greeted with mixed reactions and confusion on the PGA and European Tours. Phil Mickelson has found a way around the ban on "U"-shaped grooves by playing with a 20-year-old Ping wedge. Tour player Scott McCarron has claimed that its "cheating" to use them.

The new regulation shrinks the volume and softens the edges of the club head grooves. Mickelson was among at least four players at Torrey Pines last week who used the Ping wedges, which have square grooves. 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 20-year-old McIlroy will defend his title at the Desert Classic on Thursday. He'd prefer other ways to make golf more difficult rather than tampering with club design.

"I think they are trying to bring the whole professional game and the amateur game closer together," McIlroy said.

McIlroy acknowledged that more difficult scoring at professional tournaments could cause golf to lose some spectator appeal.

"When I turn on the TV and I am watching a tournament, I don't like to see guys struggling for pars all the time," he said. "I think people like to see birdies as well."