Diamanti, 31, moved to the Chinese Super League from Bologna in February and missed out on Cesare Prandelli's 30-man squad.
But the former Bologna and West Ham playmaker believes joining Marcello Lippi's team was not why he missed out on selection.
"I don't think being in China had anything to do with that," 17-time Italy international Diamanti told La Gazzetta dello Sport.
"I believe Cesare Prandelli made a tactical choice."
Diamanti admitted the money on offer was part of the reason for his move, but said he maintained his professionalism throughout the negotiations.
"I left in a very strange situation, as I found out Guangzhou wanted me on December 26 and Bologna alerted me on January 4," he said.
"After turning down so many clubs over three years, for the first time I said I'd like to try this new international experience with my family. I was also attracted by the economic package, I'm no hypocrite.
"On January 24, the negotiations terminated and for me the matter was over. I continued doing what I had always done with great professionalism. It was said that I already knew I’d leave and was thinking about Guangzhou, but that isn’t true.
"After my last game with Udinese, (Bologna) coach Davide Ballardini said everyone should be as professional as me. I never asked to leave, made threats or threw tantrums, because that isn’t my style."
