That sees him lie T16 after day one.
The former World No.1 was last seen using the SIM2 Driver earlier in the season before switching into the ZX5 Driver.
TaylorMade launched its SIM2 Driver in January 2021, so it's coming up to being a three-year-old driver now.
As for whether Koepka will have the TaylorMade SIM2 Driver in his bag in Rome next week remains to be seen but it's an interesting observation nonetheless with just a week remaining until the biennial contest between Europe and the United States.
Koepka will be the only LIV Golf League player competing at the 2023 Ryder Cup.
Brooks Koepka WITB | LIV Golf Chicago 2023
Driver: TaylorMade SIM2 (10.5 degrees; Mitsubishi Diamana D 70 TX)
3W: TaylorMade M2 Tour (16.5 degrees; Mitsubishi Diamana D+ 80 TX)
Irons: Nike Vapor Pro (3; Fujikura Pro Tour), Srixon ZX7 MKII (4-9; True Temper Dynamic Gold Tour Issue X100)
Wedges: Cleveland RTX ZipCore Tour Rack Raw (46 degrees; True Temper Dynamic Gold Tour Issue X100), Cleveland RTX6 ZipCore Tour Rack (52, 56, 60 degrees; True Temper Dynamic Gold Tour Issue S400)
Putter: Scotty Cameron Teryllium TNP2
Ball: Srixon Z-Star Diamond
Koepka received one of Zach Johnson's six captian's picks in the United States team last month.
He will be making his fourth straight US Ryder Cup team in Rome.
Team USA are bidding to win the Ryder Cup for the first time on European soil since 1993.
They are the defending champions, however, having lifted the Ryder Cup in record-breaking fashion last time out with a 19-9 romp at Whistling Straits.