The Dutchman made his full debut in Kazakhstan and came close with two headers but Celtic found themselves on the end of a shock 2-0 defeat.
However, the 22-year-old refuses to believe they have blown their chance of making the group stage.
"At Celtic Park anything can happen and we're definitely still in it," he told Celtic's official website.
"We have the fans behind us and that's the biggest thing for us. It's not over.
"We created a lot of chances in the first game and had a lot of the ball, but now we have to make sure we do the job at Celtic Park.
"People here give me confidence and we're all determined and motivated to turn the tie around. We're going to do everything we can to win the game and the tie.
"We need to keep believing. Every supporter always stands behind us, and I'm sure that's going to be the case on Wednesday."
- Sports & Recreation