The full-back feels that the Rossoneri could easily have snatched a win in Wednesday's game, and was delighted with his personal contribution to the game
The Rossoneri put in a strong performance to hold the Spanish giants to a scoreless draw in the first leg of their quarter-final tie, but Antonini feels that things could have been even better for Milan.
"If think it was a strange game as both sides had good chances to score but both failed to take them. I think our chances were even bigger than theirs," Antonini stated to the official Uefa website.
"We prepared well for the game, we knew how to face them and we did it in the best possible way.
"We played better in the second half, showing that our physical condition is good. We are getting some players back from injuries and we can only get better."
The full-back played a key role in shutting the Barcelona forwards out as he denied Alexis Sanchez in the 35th minute.
"I saw Sanchez starting his run and fortunately I was prompt enough to start running just after him.
"He is very fast but I managed to take him. After my tackle I celebrated as if I had scored a goal because I think it was an important action at a key moment of the game."
Milan resume Serie A action on Saturday when they travel to Catania.