The MotoGP star, repeating last year’s popular guest appearance at The Bend Motorsport Park, had earlier progressed from eleventh place (+1.634s) in FP1 to fourth (+0.458s) in FP2.
But the 27-year-old was among several riders to fall in the closing stages of FP3, leaving him 14th in the session and eighth on the combined Friday timesheets after being unable to better his 1m 51.976s FP2 time.
Cru Halliday topped Friday’s Alspinestars Superbike timesheets with a 1m 50.969s in the final session, putting him 0.153s clear of Arthur Sissis. Championship leader Mike Jones completed an all-Yamaha top three.
Miller was not the only Thriller Motorsport rider to hit the ground with Josh Hook injuring his wrist after falling due to an electronic issue with his Honda at the start of FP2. Hook remains in doubt for Saturday.
The third Thriller-backed entry of Marcel Schrotter, riding a Yamaha, was 17th, just behind Moto3’s Joel Kelso (BMW).
Miller, who took a podium in last year’s ASBK event, is again riding a Ducati Panigale V4R Superbike but has switched from Michelin to Pirelli tyres for this weekend’s return.
The four-time MotoGP race winner continues to use the Panigale’s standard electronic system to avoid any issues with the MotoGP testing regulations.
In 2020, Fabio Quartararo was forced to sit out part of opening practice at the Spanish MotoGP as punishment for some winter training laps on a Superbike fitted with modified race parts.
Such restrictions are in place to prevent MotoGP riders from conducting clandestine technical development by ‘training’ on a Superbike fitted with certain MotoGP-applicable components, such as electronics.
Qualifying at The Bend takes place on Saturday with the races on Sunday.
After five seasons in MotoGP with Ducati, Miller is switching to Red Bull KTM for 2023.