The limp was barely perceptible to anyone behind the ropes, but, in Padraig Harrington's mind, the old ankle injury that had flared up was akin to someone hammering away on his bones, a bit like a blacksmith diligently and relentlessly knocking a horseshoe into shape.

Each step was taken with extra care, and every time he swung the club Harrington's mind was reminded of the need to be careful about transferring weight on to his left foot. For a golfer in the midst of the US PGA Championship the recurrence of the injury couldn't have come at a worse time.

"It's not very easy to hit a golf ball off your right leg," said Harrington, who shot a second round 73 for level-par 144. "I'm getting stuck on my right side, hitting it a hundred yards right and 50 yards left. Subconsciously I can't put my weight through, and trying to do it consciously is not helping me to hit the ball either."

All in all, yesterday's second round was a grind; a time to battle his way around the course and, instead of aiming at the title itself, ensuring that he would survive the cut, which he did.

The injury is an old one, first suffered when he twisted his ankle on a bad piece of land on a course in Portugal a decade ago.

"I damaged it badly but didn't treat it properly for a couple of weeks," recalled Harrington.

Five years ago, when he had a bio-mechanical physical assessment, the consultant noticed the old injury and, as a result, Harrington has spent a considerable amount of time in the gym attempting to build up the balance in the left ankle.

Every so often, the injury would return; and when he went over on the ankle when he stood on a branch in rough during the Dutch Open almost three weeks ago he aggravated it. When he arrived here in Minnesota earlier in the week, he didn't believe the injury would be a factor, however. He had it strapped as a precaution when playing his practice rounds, but it was only after having treatment that it really flared up.

"I felt great on Monday and Tuesday, and then I went to the physio-chiropractor and had some treatment. I knew having treatment might flare it up, so I asked was it wise. I was told that yes, for the long term, you've got to get in there and work it out. I was wary that by flaring it up a little it would be in my mind, and I started to hit it sideways in practice on Wednesday and I've followed up nicely in the first two rounds, haven't I?

"It's not a severe pain, but it is hard trying to swing a club. I don't want to go onto my left side, and have to force myself, and that is distracting me from swinging the club. All I can hope is that it will go away, that when I get up tomorrow it will be gone. I hope."

After his round, during which he battled gamely and rescued a score with some short game scrambling which produced nine single putts, Harrington was to be found on the practice range working on transferring his weight onto his left, although he has a real uphill fight to get back into championship contention.

"I certainly wanted to be a few shots better," he conceded, "but level par is very good considering how I've played. "

Over the two days, Harrington has only found 13 of 28 fairways and, consequently, only found 19 of 36 greens in regulation.

"If there has been any good to come out of this, it is that I have putted well, and it is nice to know you can putt well even when you're struggling."

At least Harrington will be around for the weekend. Darren Clarke, who had opened with a 79, looked to have played his way towards survival by registering five birdies and alone bogey - until he stood on the 17th tee.

However, he finished bogey-bogey - to sign for a 70 and a 36-hole total of five-over-par 149 - which left him outside the cut.