"Basically I saw it coming after winter testing, this is the best we could do," the 19-year-old Dutch driver told Sky Sports television on Saturday after he qualified fifth behind the two Mercedes and Ferraris for the season-opening race.
Australian team mate Daniel Ricciardo was 10th after spinning into the tyre wall in the final phase of the session without setting a time.
Verstappen said the car had a tricky balance and lacked pace.
"We are still down on power but also, in terms of grip level and things, we are not on the same level compared to Ferrari and Mercedes yet," he said.
"Our best hope tomorrow is a clean start because we don't have the pace to challenge the Ferraris and Mercedes. I'm realistic."
Read the full article on eurosport.co.uk: Verstappen says Red Bull not on same level as rivals