Ian Poulter admits he cannot get the Ryder Cup out of his mind despite making light of a lack of practice to make a superb start to the 100th US PGA Championship.

After being away from his Orlando base since May 20, Poulter flew home after finishing 10th in the WGC-Bridgestone Invitational on Sunday rather than heading straight to St Louis for the final major of the season.

The 42-year-old only travelled to Bellerive Country Club on Wednesday and played just nine holes in practice, but still carded an opening 67 to lie two shots off the early clubhouse lead held by playing partner Rickie Fowler.

"I saw the weather forecast saying it was going to be 97 degrees on Monday and I don't normally play golf on Mondays anyway," Poulter said. "And then I saw the storm possibilities on Tuesday and Katie [his wife] and the kids were arriving home on Tuesday afternoon.

"So for me it made sense to go home, have a rest, unpack, fill the fridge full of food and have a couple of nights' sleep in my own bed and come up early Wednesday morning.

"I played the back nine and then I walked around the front nine and hit some chips and putts. You can see everything. You can see the bunkers, landing areas. And especially when it's as soft as this it's not like you need to know too much about how the ball is going to land into the greens."

Poulter would appear a certainty for one of European captain Thomas Bjorn's four Ryder Cup wild cards after an excellent season which included his first win since 2012 in the Houston Open and a return to the world's top 50.

But the Ryder Cup talisman would still like to qualify automatically for September's contest at Le Golf National in Paris, where Europe will try to regain the trophy lost at Hazeltine in 2016.

"I'm close, but I need a little push," Poulter added. "I could have got it done last weekend. That's why I'm a little frustrated that I didn't, but I think I can squeeze in if I play well here and it would be fantastic.

"I'm trying not to think it, but I know it's there. I'm close enough now where one good week in the next two weeks can push me in. It's on my mind. I want to be there in Paris. So hopefully we can make it."

A change of shirt paid, meanwhile, dividends for Tiger Woods as he recovered from a nightmare start to his opening round.

Woods, who is seeking a 15th major title and a first since 2008, was among the early starters hoping to make a flying start in baking temperatures in St Louis, only to drop three shots in his first two holes.

But after changing his shirt in a players' bathroom between the 11th green and 12th tee, Woods fought back to card a level-par 70 to lie five shots off the clubhouse lead.

Fowler carded six birdies and a solitary bogey in a 65 which gave him a two-shot lead over Poulter, former world No.1 Jason Day, Austin Cook and Pat Perez.

Defending champion Justin Thomas had been three under after six holes before two bogeys on the inward nine meant he had to settle for a 69, while Rory McIlroy parred his last nine holes in succession in his 70.

Starting on the back nine alongside Thomas and McIlroy, Woods missed the fairway with his drive on the 10th, a par four of more than 500 yards which plays as a par five for the members.

From a bad lie in the rough Woods opted to simply pitch out on to the fairway and, after a poor approach and weak first putt, did well to hole from six feet for a bogey.

Woods also missed the fairway on the 11th and saw his approach find the water in front of the green, but after a mediocre pitch from the drop zone led to a double bogey, a superb approach to the next set up a tap-in birdie.

The 42-year-old did well to save par on the 15th after pulling both his tee shot and attempted recovery into the crowd, but was unable to repeat the feat on the par-three 16th after another wayward approach.

However, Woods did hole from three feet for birdie on the 18th and 10 feet on the first and another birdie on the par-five eighth completed a superb comeback.

Woods was delighted to have turned his day around and remain in contention for a first victory since 2013.

"It kept me in the golf tournament," Woods said. "It could easily have gone the other way but I hung in there and turned it around. I'm just happy to be within five [of the lead] right now.

"I just had to grind my way around this place. I tried to stay as patient as possible after I got off to a terrible start and tried to eat away at it. These are four long days; it's a marathon."

Asked about his change of shirt, Woods added: "I was going to change before the start but there wasn't a place to change on the 10th tee so I waited until there was a toilet.

"I sweat a lot in the summer and lose a bunch of weight; I've tried everything and just sweat a lot."