“The knee is not great Rory”Padraig Harrington opted to take it easy ahead of next week’s US Open by pulling out of the pro-am at the St Jude Classic in sweltering Memphis.

The Dubliner, 38, had keyhole surgery on his right knee just over two weeks ago and he faces a major test of his fitness over the next four days at TPC Southwind.

Physical therapist Dr Mike Voight checked Harrington’s knee on Monday and gave the Dubliner the green light to play nine holes practice in high temperatures on Tuesday.

However, Voight advised the triple major winner not to over-stress his knee by playing again before Thursday’s first round.

Failing to play in a PGA Tour pro-am without a valid medical reason can result is disqualification from the tournament.

But tour officials confirmed last night that Harrington was clear to tee it up alongside American Ryan Palmer and Japan’s Ryuji Imada at 1.38 pm Irish time today.

Harrington, who won the 2008 Open at Birkdale with a bad wrist, expected to be back to full fitness within 28 days of his knee operation.

He had his intervention 16 days ago (May 25), which means he should be okay in time for the start of the US Open next week.

He’s also aware that winning the US Open on one leg is not impossible after Tiger Woods pulled it off at Torrey Pines two years ago.

Lee Westwood, Rory McIlroy and Ian Poulter are the other top ranked players in Memphis hoping to break a US Open jinx.

Unlike the other three majors, no-one has managed to capture US Open after winning the previous week.

But McIlroy is hoping to build on his share of 10th in the Memorial Tournament at Muirfield Village last week.

He said: “I played nine holes yesterday, played 18 today. And the golf course is just set up great. It’s going to be tough all week. And it looks like it’s going to be pretty steamy. 

“You know, and it’s good preparation for the U.S. Open, tough conditions. You gotta hit the ball well; you gotta drive it in the fairway. You gotta put yourself in good position on the greens, so I’m really looking forward to it.”

Feeling good about his game, McIlroy added: “Obviously the win a few weeks ago gave me quite a lot of confidence, and to play well last week at Memorial was nice. And I played pretty well out there in the pro am today, so I’m pretty confident, pretty high hopes going into this week.

“I had a little bit of a down at the start of the year, but then I got pretty low after the Masters, missing the cut there. I was pretty disappointed about that, but coming back two weeks and after winning at Quail Hollow got me going up again. 

“I’ve tried to keep it there and I’m just trying to get myself a bit higher in the FedExCup and trying to stay around the Top 10 in the world rankings will be pretty good.”

As for his chances of paying a visit to Elvis Presley’s mansion at Graceland, McIlroy said: “I don’t know if I’ll have the time. I’ll be pretty busy practicing here trying to get my game in good shape.”