The two sides have already met and it was GB who took the early scalp, beating the Slovenians 63-56 in a test game in Seville. The result was even more significant given Britain triumphed without Freeland, Rob Archibald or Pops Mensah-Bonsu.
Slovenia have competed in every European Championship competition since their debut in 1993 and this summer their roster boasts two NBA players; Goran Dragic of the Phoenix Suns and Beno Udrih of the Sacramento Kings, while LA Lakers' Aleksander Vujacic was cut from the squad last month, despite having turned out against Britain.
"Slovenia will be huge because we have got them first game and I think it will be our one chance to get out of the group," said 22-year-old Freeland.
"With it being our first game we will be fresh and won't be tired as if we had two or three games under out belt. From the other game I felt we played so well and that is already giving us confidence.
"As long as we give 110% and go all out I feel confident we will win. Beating them the way we did in Spain was a massive boost and it means that we already know we have it in us to win.
"I really feel like Slovenia is our one chance. They will have their players coming in, but we already beat them when their NBA guys were playing.
"If you look at their team they are unbelievable. It's packed with high level players from NBA and ACB which is why it was incredible how we came together and came up against competition like that and showed professionalism in the game.
"I feel that if we can get that win against Slovenia then it would give us real momentum moving into the next game, even if that is against Spain."
Freeland, who will play alongside Archibald at Malaga next season, admits it has been a tough summer so far for the British side. With the level of competition considerably higher GB have only recorded one win in nine games, but Freeland believes results aren't important at this stage.
"It's been a tough campaign so far, we've had to deal with a lot of things going against us while at the same time taking on better opposition. Even Israel, whom we beat last year, was a tough game.
"Obviously we would love to have results on our side but the main reason we play these games is to get better and try to achieve goals for Poland. I feel comfortable looking at those games we have done wrong in and keep working on what we need to.
"Nothing has been going in our favour much; now most of the guys have been ill. I couldn't play two games in Turkey because of this bug. It's just made it tougher because for all the games we have not had a full squad, but that means Poland will be exciting to see what we can finally do when everyone is fit.
"If teams don't treat us with respect then it will be to our advantage. Any team that acts off us we will jump on them.
"The team is different from year to year but I feel there's definitely more chemistry going into this year to last. Everyone knows everyone and everyone knows the way we each play. We will definitely cause some shocks; we're ready to play that's for sure."
log on to bbc.co.uk/basketball or hit your TV red button at the following times to watch the games live:
Monday 7 September, GB v Slovenia, 17:15
Tuesday 8 September, GB v Spain, 20:00
Wednesday 9 September, GB v Serbia, 20:15
