Piastri was third fastest in the opening practice session of the season behind Daniel Ricciardo and Lando Norris, a result heavily influenced by a soft tyre run when most didn’t.
However, he backed that up with fifth in Free Practice 2, when the field did complete performance runs.
He was one place, and half a tenth, faster than championship-favourite Max Verstappen.
“I think we’re kind of in the mix,” Piastri said at the conclusion of the day’s running.
“Red Bull don’t look quite as quick as we thought, we’ll see how many sandbags come out tomorrow.
“It’s a lot closer than I expected,” he added
“ Mercedes looks quick, Fernando [Alonso] looks quick.
“Always a bit hard to judge on a Friday but I think sort of around the point, and I think with the teams we’re around, being near the podium or near 10th is very much a possibility.
“Hopefully, we can stay towards the front end of that mix.”
While Piastri’s performance showed promise, he warned that the car is far from perfect and aspects still needed work.
“Definitely in FP2 I think it felt good,” he said of the car’s performance.
“Both in the qualifying style runs and the race runs, I think we’re in a decent place.
“Still a bit inconsistent and up and down, so it’s a bit hard to know exactly how we’re going to fare, but it looks a bit of a similar story for everyone.
“There’s some runs that we need to look at in more detail as to why they were how they were, both good and bad, but no, I think the overall feeling of the day is pretty positive.”
Practice continues in Bahrain tomorrow (Friday) with a final 60 minutes of running at 15:30 (23:30 AEDT) ahead of qualifying at 19:00 (03:00 AEST Saturday).