Piastri ended Free Practice 2 in 12th after electing not to run a set of soft tyres in the second hour of running. That left him 1.088s off the pace set by Ferrari’s Charles Leclerc.
Earlier in the day, the Australian was second fastest, just 0.029s behind Mercedes’ Lewis Hamilton in a session that offered a better like-for-like comparison.
“We ran a set of softs in FP1, you only get a certain amount of sets of softs for the weekend, so we’re trying to prepare for qualifying tomorrow,” Piastri explained of his Free Practice 2 approach.
“We thought that, at the time, there was a high chance of rain for FP2, so we wanted to get some softs running in early.”
The 23-year-old chalked Friday’s running up as a positive day for himself and the team, though noted the increased competition towards the front of the field this weekend.
While Ferrari and Red Bull Racing were expected to be fast, Mercedes showed strongly, and even Aston Martin demonstrated pace, with Fernando Alonso third fastest in Free Practice 2 and Lance Stroll seventh fastest.
“Ferrari looked quick, Red Bull looked good, Mercedes looks a lot stronger this weekend, so far, so it’s very tight at the front,” he noted.
“Honestly, we could be first and we could be eighth,” he added on where he might end up in qualifying.
“Even Aston looks pretty decent, Alonso looks good, so it could be first, it could be 10th. You never know.
“It’s been very, very tight between everyone today, so we’ll try and tune up the cars for tomorrow, give it a good run and I think it’s going to be exciting.”
With the top five teams seemingly so evenly matched, Piastri suggested the difference could come down to the driver.
During Friday’s practice, the Melburnian found the limits, harmlessly kissing the barrier in the process.
“I’ve been pretty happy with how I’ve driven today, a couple of touches on the walls aside,” he admitted.
“When I touched the wall was in probably the worst place to touch it, in that chicane, so I’ll try not to do that again.
“I think it’s very much in the drivers’ hands,” he added of qualifying.
“It looks like there are a lot of quick cars out there, so whoever nails the lap is probably going to end up on pole.”
A final hour of practice awaits teams and drivers, starting at 12:30 local time on Saturday (18:30 AEST) ahead of qualifying from 16:00 (midnight AEST).