CNN  — 

Jon Rahm may be one of the bigger hitters on the PGA Tour, but having a short memory is a trait the Spaniard values even more.

“Happiest animal in the world is a goldfish. You know why? He’s got a 10-second memory,” Rahm said, quoting a line from the popular “Ted Lasso” series.

“I played great golf last week, just a couple of bad swings down the stretch, and that’s the most important thing to remember.”

The world No. 1 was speaking after his opening round at the BMW Championship on Thursday, where he finished tied atop the leaderboard with Rory McIlroy and American Sam Burns.

The two European Ryder Cup teammates and Burns carded eight-under 64s at Caves Valley Golf Club in Baltimore, Maryland, for the share of the lead in the second event of the FedExCup Playoffs which will determine the PGA Tour’s season champion on September 5.

An eagle on the par-five 16th hole for McIlroy shot him up the rankings and into a share of the lead. The Northern Irishman is 28th in the FedExCup rankings, with only the top 30 making it to the season finale – the Tour Championship – next week.

“I’ve went through playoff stretches before where you’re always in that lead group. You’re either 1, 2 or 3 in the FedExCup, and that can sort of take its mental toll,” he said. “I’m in a position where I need to play well just to play next week. There is an element of freewheeling.”

Both Rahm and Burns carded bogey-free rounds on Thursday, and with both set for East Lake next week for the Tour Championship, maintaining their good form is paramount.

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McIlroy looks on over the first green during the first round of the BMW Championship.

‘It was brutal out there today’

For US Open champion Rahm, his opening round continues his hot form. According to the PGA Tour, it was the 15th time in his last 17 rounds that he shot in the 60s.

While Rahm’s clubs remained on fire, it wasn’t the hottest thing at Caves Valley on Thursday.

Temperatures were consistently around 90 degrees and coupled with high humidity and elevation changes, conditions proved difficult for the players.

Cameron Smith, the Australian who finished second after a playoff with Tony Finau at the Northern Trust last week, explained that the speed at which he was walking was something going through his mind during Thursday’s round because of the “brutal” conditions.

“We were probably walking a bit slower than what we typically do and trying to find shade a lot … it was brutal out there today,” Smith said after his four-under 68. “Those last probably four or five holes, it gets to you and you start thinking, ‘When is this going to end?’ You’ve just got to be smart about it.

“I’m from Queensland where it gets hot, so it doesn’t really bother me, it just takes a lot out of me. So now I’m looking forward to a quick massage, then a cold shower and a couple cold beers.”

Rahm thanked the fact he had a Covid-enforced month break after the 2020 Olympics for maintaining his energy levels.

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Rahm hits a shot on the first tee  during the first round of the BMW Championship.

“Those guys that went to the Olympics and played Memphis and played more events than me may be a little bit more tired, but really that shouldn’t be an excuse in my case,” he said.

“On Tuesday when I came to the course, I didn’t do too much. I didn’t even venture out on the golf course because I knew it was a tough walk. I just hit some balls, a little bit of putting and chipping and went home.

“On days like that what I really prioritize is hydration. If you get dehydrated in the middle, it’s going to affect you over the next few weeks.”