Netzer, 70, recently visited Hoeneß, who is four months into a three-and-a-half-year sentence, at Landsberg prison near Munich.
Hoeneß resigned as Bayern's president in March, 24 hours after being sentenced, having admitted to evading €28.5 million in taxes.
Netzer told the Rheinische Post that Hoeneß, 62, is doing well and is said to have lost 20 kilos in weight since starting his sentence in June.
"He was in good shape when I saw him and was proud of his weight," said Netzer.
The friends were part of the West Germany squad which won the 1974 World Cup title and Netzer said Hoeneß is doing his time with dignity.
"I have the greatest admiration for him, because he has mastered his situation," said Netzer.
"He has accepted it and is living exactly according to the guidelines. He has no privileges and doesn't want any."
Hoeneß can expect to be released from prison after around 21 months for good behaviour.
The former midfielder has also been visited in prison by Bayern chairman Karl-Heinz Rummenigge, former coach Jupp Heynckes, current Munich coach Pep Guardiola and France winger Franck Ribery.