Verstappen and team-mate Sergio Perez finished second and third respectively in FP2, narrowly behind Aston Martin's Fernando Alonso.
But neither had a smooth day after Red Bull lost the car balance during FP1 and only got into a reasonable window well into FP2.
Rather ominously, it meant that neither Verstappen nor Perez have been able to unlock the car's full potential, with Verstappen admitting he hadn't found his groove yet. He therefore was surprised that both his short and long run pace was as competitive as it was.
"Yeah, difficult start of the day," Verstappen said.
"FP1 was really bad, I just couldn't get a balance, which was a bit odd because in testing whatever we tried... some things were maybe not amazing, but not that far out.
"So, a few things to understand, even the start of FP2 was a bit difficult.
"But then I think for the final run, even though not really having a good reference and confidence up until then in the car, the lap was not too bad in the short run and also the car felt a bit more connected.
"And then in the long run, with all the changes we made, I was quite surprised that it was the pace we had.
"I just need to find my rhythm again with the car and and just the way the car is driving from short run to long run."
Verstappen was still confident that when Red Bull gets its set-up right he will be "very fast" in qualifying trim.
"If I feel happy in the car again and that I can push like I want to push with the car on one lap then, for sure we are very fast," he explained.
"But it's also of course making sure that the car doesn't fall out of the window for the long run."
When asked about Aston Martin's table-topping pace, Verstappen's team-mate Perez felt Alonso's headline-grabbing time just confirmed what rivals teams were already seeing during testing.
"We knew from testing already that they were going to be very strong that they were going to be very competitive," the Mexican said.
"No surprises to be honest, I think it just confirms how strong they are.
"I think everything is tight at the top. The Astons, the Ferraris ... I think it's going to go down to who puts the best lap together and obviously, who has the better race pace on Sunday."
Verstappen added: "They are quick, but you could see that already in testing that they were very competitive, so yeah, they had a great day.
"For us there's still a bit of work to do. We know that we have a very competitive car just now putting all the pieces together."
