PGA CHAMPIONSHIP RELATED STORIES PGA Championship Home Page PGA Championship Preview Round 1: Karlsson & Singh top leaderboard Round 1: Ernie Els recovers to stay in contention Round 1: Westwood unhappy with course set up Round 1: Sergio Garcia happy despite poor driving Round 2: JB Holmes edges ahead at half way Round 2: Montgomerie slumps to worst round Round 2: Michael Campbell shows a return to form Round 2: Phil Mickelson warns leaders Round 3: Rain ruins play on Saturday Round 3: Romero ties course record with a 65 Round 3: Weir rates 2008 majors toughest yet Round 3: Oakland Hills leaves Azinger with puzzle Round 4: Harrington lifts his third major title Round 4: Garcia loses out to Harrington again Round 4: Curtis misses PGA but makes Ryder Cup Round 4: Mickelson fails to plug the Tiger gap Course Guide: Oakland Hills PGA Championship Scores PGA could be toughest test of the year Sergio Garcia still searching for first major US Ryder Cup qualifying ends this week Par 3's key at Oakland Hills Players eager for PGA Championship Europeans positive about Oakland Hills Steve Stricker has eye on Ryder Cup place Phil Mickelson trying to make year a good one Trevor Immelman trying to find consistency John Daly still a fan favourite Lee Westwood hoping for a breakthrough Memorable quotes about the PGA Championship 2008 PGA Tour Schedule NEWS & TOUR TOP STORIES Nick Faldo receives his Knighthood LPGA wins Wendy's 3-Tour Challenge Mickelson raises expectations for 2010 Race to Dubai nears its conclusion Thousands follow Tiger Woods practice round Fans warned about fake Ryder Cup tickets COMPETITIONS, GIFTS AND OFFERS WIN 2 nights/3 rds at The Vale Resort £10,000 of Teeofftimes prizes in April! WIN Healthspan Supplements WIN tickets to the National Golf Show! Open Champion Tom Watson's DVD Get the Open Fairways card for just £59!

Phil Mickelson warns leaders

Phil Mickelson sent out a warning to the leaders after a frustrating day at the PGA Championship on Friday.

The world number two shot a second-round 73 to finish four shots behind leader J.B. Holmes.

“I think it gets more difficult in the afternoon, so the leaders are going to have a harder time tomorrow,” Mickelson told reporters.

“As the greens get firmer or crustier and bumpier and the ball doesn’t check and you can’t hit it firm enough, all of the guys who are in the lead and the top half of the field will have a tougher course tomorrow afternoon.”

Three-times major winner Mickelson, the 2005 PGA champion, echoed the view of many players that this PGA was playing as tough as the usually penal set-up for a U.S. Open.

“It’s similar, very similar to what we see at Opens normally,” the 38-year-old American said.

Mickelson said many factors contributed to the struggle to make par. For the second successive day, the scoring average at Oakland Hills was nearly five over.

“I think that the raking of the grain of the grass away from the green has made it very difficult,” he said about preparations of the rough that made it harder to advance the ball.

“And given the fact that the greens are firm and fast, and you can’t control it, you can’t control your spin, it is difficult to get up-and-down,” said Mickelson, a noted master of the short game. “I have really struggled around the greens.”

Mickelson stopped short of calling conditions unfair.

“I’ve got two more rounds to go. So I’ve got to play this thing two more times and I don’t really want to get into whether or not it’s fair or what have you.

“Everybody’s got to play it.”