It will be Koepka's ninth week as the world's top-ranked player.
The 29-year-old American owned a seven-stroke lead over world number one Dustin Johnson and Thailand's Jazz Janewattananond, his only rivals within nine shots.
It happened at the PGA Championship after defending champion Koepka fired a five-under par 65 at Bethpage Black on Friday to seize a seven-stroke lead on 12-under 128.
Third-ranked Koepka, a runaway favourite to capture his fourth major title on Sunday, fired a five-under par 65 Friday at Bethpage Black to stand on 12-under 128.
That left third-ranked Koepka sharing the lead with England's Tommy Fleetwood, trying to become the first Englishman to win the event since Jim Barnes in 1919.
Woods, who ended an 11-year major win drought last month at Augusta National, competes for a 16th major title starting Thursday at the 101st PGA Championship at Bethpage Black.
Immesberger was a bartender at The Woods and knew the golf star personally, according to the report.
The start of play on the Dallas, Texas, course was delayed six hours because of heavy rain that lasted through the night and into the morning.
The 43-year-old American superstar completed one of the great comebacks in sports history last month with a dramatic victory at the Masters for his fifth green jacket and first major triumph since the 2008 US Open.
The PGA of America hopes Woods winning the Masters last month at age 43 and chasing a 16th major title can boost lagging participation numbers the way his first major win did at the 1997 Masters.
The 33-year-old, who has six professional wins but who played in only one major in 2018, said he was taking a leave after suffering multiple relapses.
Golf has overcome a few bumps in China, where it was banned until the 1980s under the orders of Mao Zedong, who decried it as a bourgeois "sport for millionaires".
The Finn shot a superb six-under par 66 to finish at 20-under par for the tournament alongside overnight leader Hebert.
The Finn shot a superb six-under par 66 to finish at 20-under par for the tournament alongside overnight leader Hebert, who had a three-under 69 at Genzon Golf Club in Shenzhen.
A black superstar in a white-dominated sport, Woods has also generally avoided commenting about race relations in the United States.