ATHENS — He is known as the Greek Freak, a basketball player of such transcendent ability that he has become celebrated as the face of the country of his birth. Yet for most of his life growing up in Greece, Giannis Antetokounmpo was considered a foreigner. As the son of African immigrants, he was perpetually vulnerable to attacks by racist militants, and to threats of deportation to Nigeria, a country he had never visited.

As Antetokounmpo now commands the stage in the N.B.A. playoffs as the best player on the Milwaukee Bucks, the top-seeded team in the Eastern Conference, his fellow African immigrants in Greece are watching with rapt attention. His story — the tale of a teenager who could barely dribble turning himself into one of the supreme basketball players on the planet — is the source of admiration and joy. Yet it is also cause for bitter reflection on the enduring discrimination suffered by his community. Many lament that Antetokounmpo’s experience has become fodder for a fairy tale about Greek life in which his struggles have been edited out.

Until recently, even the children of African immigrants who were born here found it difficult to secure legal residency, let alone citizenship. Their stateless status denied them national health care, Civil Service jobs and access to sports leagues. Antetokounmpo only gained Greek citizenship six years ago — just as he was about to go to New York for the N.B.A. draft.

“He was given Greek citizenship in order to prevent him from traveling to New York as a Nigerian,” said Nikos Odubitan, the founder of Generation 2.0, an advocacy group that helps second-generation immigrants gain legal status in Greece.