Poulter, who is playing for the fifth consecutive week, justified his decision to arrive at Bellerive on Wednesday following a couple of days at home as he fired a solid three-under 67 to lie just two shots behind early leader and playing partner Rickie Fowler.
The Englishman coped well with the heat and humidity at the St Louis venue, making birdies at two of his first three holes and picking up another at the 15th, but he took the gloss off an encouraging back-nine when he missed the green from a little over 100 yards at the long 17th and ran up a disappointing six.
Finding a fairway bunker from the tee at the fourth cost him another bogey, but he bounced back with a pair of 12-foot putts for birdie at the seventh and eighth before getting away with a blocked drive at the ninth to salvage a par.
Explaining his late arrival, Poulter said: “I saw the weather forecast for Monday, Tuesday, heat-wave coming through. I don’t normally play golf on Mondays anyway, and then I saw the storm possibilities on Tuesday.
“So for me, it made sense to go home. I hadn’t been home since the 20th of May, so it was good to get back, 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 got out on the course. I played the back nine, and then I walked around the front nine and then hit some chips and putts around that front side. So I feel relatively refreshed after just a couple of days at home as this is five weeks in a row. So it’s a lot of golf.”
Poulter also admitted the prospect of earning automatic qualification for the Ryder Cup next month helped him stave off the effects of fatigue.
“It keeps you going,” he added. “It’s been a good run, and the only disappointment was obviously at The Open. So putting myself on the board is great. It’s great for your adrenaline, it’s great for your mindset, it’s good for your confidence levels, and it keeps edging me closer to making the Ryder Cup team. There’s definitely a lot of energy to come from that.
“But five weeks in a row is about max. Very rarely when you go more than five in a row is almost pushing it, especially in the heat. Canada was quite hot, and Akron was very hot. Obviously here is always going to be steamy.”
Poulter is currently on the fringes of Thomas Bjorn’s European team for Paris, although he could have forced his way into the top eight with a better finish to the WGC-Bridgestone Invitational last week, where he was three off the lead after 54 holes before fading with a 74 on Sunday.
“I could have got it done last weekend. That’s why I’m a little frustrated that I didn’t get it done, but I think I can squeeze in if I play well here,” he said.
“I’m trying not to think about 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. So I’m close. It’s on my mind. I want to be there in Paris. So hopefully we can make it.”