The 62-67 loss means Team GB are still looking for their first London 2012 victory but can be pleased with a much-improved performance against a side ranked 13th in the world.
But Freeland, who has just signed for NBA side Portland Trail Blazers, still feels there is more to come from the hosts.
"Turnovers are always an Achilles heel for us. We were better.. There's nothing we can do other than work hard. We can't get nervous or get out of control," he said.
"Every team we're playing is a great team. I'm sick of coming into these games as underdog. It is getting frustrating."
Neither side started the match with any real tempo but it was Team GB – who lost their first game against Russia 75-95 – who ended the first quarter 11-4 up thanks to a six-point haul from Dan Clark.
The South Americans looked a lot more dangerous in the second period but the two sides traded baskets and there was nothing to separate them at the half way mark with the score at 27-27.
Brazil finally began to edge it towards the end of another tense quarter before Great Britain edged ahead in the fourth thanks to a superb three-pointer from Nate Reinking.
The game swung back in favour of Brazil before Luol Deng scored back-to-back three pointers to put Great Britain back on top with just four minutes remaining.
In the end though, tiredness and a lack of big match experience showed and the Brazilians were able to force home their superiority and run out 62-67 winners.
Chris Finch’s side have three games left and forward Andrew Sullivan says only victory in each of them is on their minds, starting with the next match against European champions Spain.
"We matched up well with Spain (when previously playing them). We have three games left and want to win our last three games. We didn't come here for it to come down to the last two games to get through," he said.
"Pride comes with wins. We are not here for people to tell us we did a good job, we are here to win games. We didn't get it done in the end."