The 30-year-old, who is considered China's most successful football export, was shown a red card for dissent while he was warming up as a substitute.
FIFA announced on Tuesday that Sun would be banned for the next five matches and fined £3,000 for his verbal assault on the referee.
"I was surprised when I heard of the suspension," said Sun. "I just said some words, which are usually heard in the Premier League. I did not verbally abuse him or insult him.
"I do know I did something wrong at the time. But in the past, China has been disadvantaged by the referee's whistle.
"I have nothing to say as China is a constant underachiever in soccer. But I still believe the referee at that match had problems with his whistle."
The suspension also means he cannot compete for China's Olympic team at the Beijing Games, where Sun was set to serve as one of three permitted over-age players.
"Yes, it will be a long time before I show up for the national team again, but anything is possible," he said.
"I am not quitting yet and I still have the ambition to play for the national team."
Sun concluded by insisting that he intends on continuing his European adventure, even though it is looking unlikely that Manchester City will offer him a new deal.
"I still hope to play in European leagues," he said.
"The 2008 Euros shows they are playing the best soccer in the world."