McLaren's Lando Norris was second fastest in second practice for Formula One's season-opening Bahrain Grand Prix on Friday and almost as quick in playing down his team's prospects.
"We looked quick today but it's fairly obvious what's going to happen tomorrow. It's going to be kind of the usual front four cars ahead of us," the Briton told Sky Sports television.
"Behind there it seems very close, even if today we were a little bit ahead... we'll go in tomorrow and be a little bit more where we should be."
Former champions McLaren finished third overall last season, their highest position since 2012 which is also when they last won a race.
Red Bull's Max Verstappen was fastest in both sessions while Mercedes' seven-times world champion Lewis Hamilton ended the evening third on the timesheets.
McLaren have switched to Mercedes engines from Renault and Norris has been joined by experienced Australian Daniel Ricciardo.
"I feel good in the car and the car does feel good," said Norris. "In some areas also it doesn't feel that good and we need to improve."
Ricciardo said he was "still getting there" after the switch from Renault.
"I still want to find a few things in the car and obviously within myself," he said. "Hopefully I'll find another step tomorrow to get more where I want to be."
McLaren boss Zak Brown said it was not realistic to think his team could 'gate-crash' the looming battle between Mercedes and Red Bull this season.
"We hope to close the gap but I think it would be unrealistic to think that we would get in the mix on a regular basis," he said. "But we're on our way and hopefully we'll be able to join that fight in the not-too-distant future."