Thomas has barely had time to pause for breath after a frenetic finish to the campaign and will take a proper break only after playing next week's CJ Cup, South Korea's first PGA Tour-sanctioned event.
Tied with Schauffele in second place is Thailand's Poom Saksansin, a 24-year-old two-time Asian Tour victor making his first start in a PGA Tour event. He won his first tour title here two years ago. Among those with 67s who are tied for eight are Brendan Steele, last week's victor at the Safeway Open, and Davis Love III.
A three-stroke win to defend his championship underlined his pedigree, however, and was the springboard for a stellar campaign featuring five wins, a maiden major title and last month's FedExCup triumph.
He's aiming to be the first player to win the same tournament three years in a row since Steve Stricker at the John Deer Classic from 2009-11.
Schauffele, the us tour rookie of the year, said he was taking plenty of notice of how Thomas approaches this course and is trying to keep it simple.
Thomas will also be up against a quality field at the PGA Tour's second event in the 2017-18 calendar, including Japan's world number three Hideki Matsuyama, who he pipped for the circuit's player of the year award.
"The rough has been up apparently compared to previous year, that's what Justin told me", he said.
"I have to keep the game-plan pretty much the same really: just be smart off the tee, try to hit the fairways and then really aggressive into the greens". Schauffele and Poom made seven birdies to go into early contention, while Bradley eagled the 12th hole to make amends for his sole bogey.
That leaves the 24-year-old six strokes back of Day 1 leader Cameron Smith, who shot an opening bogey-free 64 to move to a one-stroke lead over a trio of golfers, including 2017 tour rookie of the year Xander Schauffele.
"The putting was easy actually", Smith said.
Smith, who broke his duck on the PGA Tour in May at the Zurich Classic of New Orleans alongside Jonas Blixt, made birdies at the third, fourth and fifth and picked up further shots at the seventh and ninth to approach the turn in 31.