Darren Clarke proved you should always beware the injured golfer after he opened with a three-under 68 to share 17th with Pádraig Harrington in the KitchenAid Senior PGA Championship in Michigan.

The Dungannon man (53) revealed he has been suffering from a string of ailments this year.

"All year, I've been injured," Clarke said at Harbor Shores. "Every week, there's been something wrong with me all year. It's been my leg, my back, I've had to withdraw from a couple of tournaments, tendonitis this week. It's been one of those years. It's been weird for me because I've gone through my whole career never being injured. I've never been an injured guy.

"This year for whatever reason, maybe it's a little bit too much alcohol or getting a little bit too old or whatever, I don't know, but I've just been injured every week.

"I've started feeling a little bit better, but my arm is still sore, and what have you. Those situations, you just have to keep playing and do as well as you can.

"It's been frustrating. I haven't even managed a Top-10 this season which has been frustrating for me. Keep finishing, whatever, 14th, 15th, around there, which I'm not out here to try can do that. I'm looking to try and play a little bit better than that."

Clarke is four shots behind Bob Estes and Steven Alker, who shot seven-under 64s to lead by one stroke from Mike Weir and Paul Claxton.

Scores

But he's hoping to build on Thursday's opening round and show more of the form he displayed in finishing tied eighth behind Steve Stricker in the Regions Tradition, the first senior major of the year, on May 9.

"I've been hitting the ball well and not scoring as well as well but hopefully starting to turn around a little bit, and like you said, a nice weekend at Tradition and hopefully I can carry on this week and get a couple good rounds and start rolling the ball better," the 2011 Open champion said.

"I've had ice packs -- I walked into the physio truck, for or our five guys are in there all the time. Physio trucks are a bit beyond my -- I don't go in there. Today when I walked in, 'What are you doing in there? You can't smoke in here.' It was one of those.

"But the guys were treating and they have helped. I'm just putting ice and taking all sorts of tablets. It is what it is. Happens when you get older, I guess."

Harrington, who was second to Stricker in the Regions Tradition before missing the cut in the US PGA Championship at Southern Hills in Tulsa, made a steady start in Michigan.

Starting on the back nine, he birdied the par-five 10th, bogeyed the short 11th but birdied the par-five 15th and par-three 17th before following nine straight pars with a birdie four to finish.

"Happy with how I played but plenty of room for improvement in my scoring," said Harrington, who has also struggled with injuries, including a knee problem.

At the top of the leaderboard, Alker continued his dream run of form as he fired an opening, seven-under 64 to share the lead with Bob Estes.

Less than nine months ago, Alker didn't have status on the PGA Tour Champions. But he has now claimed three victories, top 10s in 15 of 18 starts and more than $2 million in earnings.

"It still hasn't sunk in," said Alker, who is making just his second major start. "If you had said eight, nine months ago that I would be here, I'd probably tell you you were lying."