The 27-year-old joined the Ukrainian champions in July and has scored three times as Shakhtar sit five-points clear at the summit of the Ukrainian Premier League.
But, with the two sides set to lock horns in the Champions League Group H game, the Brazilian-born-Croatian has revealed he will refrain from celebrating, should he find the net against Arsene Wenger's side on Tuesday.
"I spent three years here and had some great moments," he said in the Mirror.
"I have respect for the supporters and Mr. Wenger. I'm on the other side now and I will give my best. I hope we can get a positive result.
"I don't think I will celebrate. I respect the club. If I score, it will be good for Shakhtar. Hopefully we can finish with a positive result.
"I am glad to come back to London again. It was great times here with Arsenal, but now I am on the other side and play for Shakhtar. I will give them 100 percent, am ready to play and will give my all best."
"Of course it was hard to leave," he added. "When you spend three years at a club you have great moments, then after that there were some problems with my injury.
"The injury is passed, I don't like to talk about that. Now I am 100 percent fit, playing football again and am enjoying it.
"I am nearly 28-years-old and I made a good decision to play for Shakhtar because they are a big club in Europe. This is life."
