Mark Webber reckons we have yet to see McLaren's true pace after the team finished over a second behind Red Bull in Friday's practice.
After topping the timesheets on Friday morning in Spain, Lewis Hamilton and Jenson Button failed to shine in the afternoon session.
Hamilton was the better placed of the two, claiming fifth place. However, he was 1.226s off the pace set by Webber's team-mate Sebastian Vettel.
"I haven't particular seen a huge amount of what has happened in that session, but for sure McLaren probably weren't showing everything today," Webber said.
As for his own Friday practice, Webber had no complaints after a "smooth" day at the office.
"Yeah, certainly a smooth one from both sides of the garage," the Aussie said. "That is a nice positive for the team. They have done a huge amount of work over the last few months, as all the teams have.
"Particularly last night, the guys worked like hell, very, very late night for our team and the boys deserve a smooth Friday. We have some stuff to go through tonight and hopefully will be well prepared for tomorrow.
"It was a good day. We had a smooth run and nice to have a good P1 and P2 with no interruptions from the weather. The guys worked faultlessly in the garage, the driver did a little bit of his work as well and it was a good day for us."