"We're feeling really good," Celtic goalkeeper Artur Boruc told Reuters. "The atmosphere in the team is great. Our preparations have gone well. We believe we will go through from this group.
"The stats show 85 percent of the teams who win their first game get out of the group. It would be good to win and be more comfortable for the next games."
Up to 50,000 Poles are expected to pour into Gelsenkirchen, set in Germany's western industrial heartland, for the second game in Group A, kicking off at 9 p.m. local time (1900 GMT).
Hosts Germany, favourites to win the group, open the tournament against Costa Rica three hours earlier in Berlin.
The Poles suspect Costa Rica may prove the group's weak point and believe victory over Ecuador would all but guarantee a second round spot.
"Every game is about three points but winning here would give us every chance to advance. Then we can relax and play better," striker Grzegorz Rasiak said.
REMAINS UNCLEAR
It remains unclear whether trainer Pawel Janas will stick with a new defensive five-man midfield that ground out a 1-0 win over Croatia last Saturday. Janas will only reveal his lineup to the players in the early afternoon.
If he returns to the 4-4-2 used in qualifying, either Rasiak or Ebi Smolarek should start alongside Maciej Zurawski up front.
Otherwise, he will drop one striker in favour of Austria Vienna's Arkadiusz Radomski as a second holding midfielder, with Smolarek and Jacek Krzynowek pushing up on the flanks.
Warsaw authorities expect a total of 300,000 Poles to cross the border for the finals and the team were cheered by several hundred early arrivals and German Poles after training at the Auf Schalke stadium on Thursday.
"We've come more than 1000 kilometres. I'm amazingly happy," said Grzegorz Kot, a marine engineer from the Baltic Sea coast.
"Four years ago was too far away and there wasn't the atmosphere you get at German stadiums. The finals won't be this close for another 20-30 years, it's like we're at home."
Media have played up the threat from Polish hooligans in the run-up to the finals but Polish and German authorities have calmed worries in recent days.
The mix of children and adults at the stadium on Thursday were in boisterous but good-humoured mood and the players said the support could prove a crucial boost.
"I feel great, it's the World Cup finals and I feel like I was at home," right-back Marcin Baszczynski told Reuters.
"We would really like for these to be 'our finals' as well as the Germans' finals. For us, for the fans, for Poland."