Iran will play Qatar on Wednesday in Tehran’s Azadi Stadium. Former Germany youth international striker will make his debut for Persians.
"I am looking forward to this experience and will try to make the best out of it," Dejagah told reporters in Germany prior to flying to Iran.
The 25-year-old went on to bemoan his side's 2-1 loss to Hoffenheim prior to his journey.
"I rather would have gone after a home victory," he said.
However, he later added he was relieved to finally be making his Iran debut, saying: "Nevertheless, I am happy it finally worked out.
The Wolfsburg striker, who was raised in Berlin but born in Tehran, has long been linked with the Iran national team but remains uncapped after previously rejecting invitations and having injury and eligibility issues.
Iran is already through to the final qualifying round, while Qatar and Bahrain are trying to book a place for the stage.