"After giving my shirt to the fans, I was about to take off my shorts as well when there was an incredible bang and a flash stunned my eyes," explained the player.
"I sat on the ground and was very dizzy, as I didn't understand what was happening. I don't know where it exploded and couldn't see very well, then the medical staff came to help me and I managed to walk to the locker room."
D'Agostino turned 29 earlier this month and has featured in all seven of Cagliari's Serie A games this season.
"I cannot say for certain what happened or if there was any damage, but I think he's alright. He was clear-headed when I saw him," revealed Cagliari Coach Marco Giampaolo.