Jenson Button is convinced Red Bull Racing remains the team to beat in Turkey despite a low-key start from the championship leaders.
McLaren driver Button topped the times in second practice on Friday, finishing ahead of Red Bull's Mark Webber and Sebastian Vettel.
Button, however, is sure Red Bull will raise its game in qualifying, having taken all pole positions so far this season.
"The Red Bulls are much quicker than they show, so it's a normal Friday. You don't catch up a second in a couple of weeks," said Button after practice.
"The car feels reasonably good around here - there are still some areas where we're not so strong, and the Red Bulls will once again be the cars to beat in qualifying tomorrow, we can't get away from that. I just hope we're closer than we've been in the last two races.
"I think the Ferrari will be quick here too. It should be the top four teams that we normally see, and possibly Renault as well, so I don't think qualifying tomorrow will be boring. There should be some good battles."
Team-mate Lewis Hamilton, quickest in the morning and fourth in the afternoon, also believes Red Bull was not showing its real form today.
"I'm sure in qualifying tomorrow they will pull something extra as they always do," he said. "The Red Bulls will be very quick tomorrow and I think the Ferraris will also be quick."
When asked if he would have a shot at beating Red Bull this weekend, he said: "I don't know. I hope so. But we haven't really made much changes to have a shot. Every weekend we have a chance, so we'll see what we can do."