There were reports he was angry at the decision and left the stadium straight after the final whistle, without celebrating alongside his teammates in the locker room.
"Tomorrow I celebrate my birthday and it's wonderful being able to do it while thinking of the victory over Inter," he wrote on his official website.
"In all honesty, considering the occasion I would've loved to score a goal myself, but Mirko made me the best present of all.
"His goal brought a very important win and finally allows us to think positive. This can be the turning point!!!