The 27-year-old Croatian forward headed to Ukraine in a £6million deal during the summer after finding himself down the Arsenal order following the free transfer signing of Marouane Chamakh.
Arsenal manager Arsene Wenger found it emotional to see the Brazil-born striker leave, after he fought back to full fitness following an horrific broken leg and dislocated ankle at Birmingham in February 2008.
Eduardo maintains the time was right for him to move on, but still holds a special affection for the Gunners.
"It was great times here with Arsenal, but now I am on the other side and play for Shakhtar," said Eduardo, signed by Wenger from Dinamo Zagreb in July 2007 for a reported £7.5million.
"I will give them 100%, am ready to play and will give my all best tomorrow."
However, Eduardo added: "I don't think I will celebrate.
"I respect the club.
"I had some great moments here and have respect for the supporters and Mr Wenger, for the club.
"I came from Croatia and learned a lot at Arsenal. Now I have more experience than before.
"When you play for Dinamo Zagreb and someone like Mr Wenger finds you, takes you to play in the Premier League, that is big respect. He believed in me.
"But now the most important thing is that now I am on the other side I will give all my best tomorrow.
"If I score, it will be good for Shakhtar.
"Hopefully we can finish with a positive result."
Eduardo believes he made the right decision to seek a fresh start.
"Of course it was hard to leave. When you spend three years at a club you have great moments, then after that there were some problems with my injury," he said.
"I am nearly 28 and I made a good decision to play for Shakhtar because they are a big club in Europe. This is life.
"The injury is passed, I don't like to talk about that.
"Now I am 100% fit, playing football again and am enjoying it."
Eduardo added: "Donetsk is a very nice city and the club is very good, the stadium is one of the best in Europe.
"There are seven or eight Brazilian guys, they help me, the boss also speaks Portuguese and so he can help. I am very happy there."
Eduardo feels his old club just need a bit of luck to go all the way in Europe.
"The Champions League is very difficult for every club, for Manchester United, for Barcelona, for Chelsea," he said.
"Every year Arsenal play the quarter-finals, semi-finals, they just need more luck to play in the final and to win."
Shakhtar coach Mircea Lucescu refused to confirm whether Eduardo would start tomorrow night.
However, the Romanian admitted: "It is bound to be emotional.
"He will be on the field - when, we will see.
"Eduardo wanted so much to play in Arsenal, he wanted to remain here, but his injury created such problems.
"Now it is Shakhtar who are helping him to come back to a big, big level.
"I hope he will return to the level he was before Arsenal.
"It could be this year, if we continue to have good results in the Champions League."
Eduardo has been utilised mostly as a substitute for his new club.
Lucescu said: "He has only played one whole match - he has to recuperate.
"Eduardo has got potential. He is a very professional player, a very intelligent and skilful player, and I hope that he will forget what happened."
Like Arsenal, Shakhtar have won both of their games in Group H.
"We are here to get a result," Lucescu insisted.
"I know Arsene Wenger very well, from when he was a coach at Nantes in France.
"We remain in contact, but this is about football and we have the same ideas."