The Ukrainian side currently sit bottom of Group G knowing that defeat to fellow strugglers Porto will terminate any hopes they have of progressing in the competition.
But Eduardo, the former Arsenal marksman, insists they are not ready to raise the white flag just yet.
"This encounter is vital to us. We perfectly understand that we have to win no matter what to still have a chance of qualifying from the group," he said.
"To finally get the first win in this Champions League under the belt is of paramount importance to us. Therefore, we are only thinking about getting a positive result.
"Everyone is in a positive mood. We are focused entirely on it, trying our hardest to put in a spectacular performance.
"I am extremely motivated to score, but the entire team must show their cutting edge and character.
"I would be happy to score, but the team winning is much more important than my personal ambition."
Porto go into the match on the back of a 3-0 defeat by Academica in their domestic cup competition at the weekend but Eduardo insists that result will have minimal bearing on Wednesday's encounter.
"Porto are an excellent side and I'm confident that at the Donbass Arena they will play different football compared to their recent Portuguese cup fixture," he said.
"One way or another we are facing a difficult match ahead. However, we are absolutely determined to claim the three points which are vital to us."
Shakhtar captain Darijo Srna is serving a one-match ban, while vice-captain Dmytro Chygrynskiy is out with a thigh injury.
The participation of Fernandinho, Willian and Andriy Pyatov is subject to late fitness tests.
Porto coach Vitor Pereira, whose side are two points above Shakhtar but three adrift of second-placed Zenit St Petersburg, has included right-back Alvaro Pereira in his squad following his recovery from tendinitis.
Porto are joint leaders of the Portuguese Liga alongside Benfica, with 24 points from 10 matches.