De Rossi feels Italy need to improve gradually.
De Rossi was beaten in the air as Alcaraz got in front of him to power home a header after 38 minutes.
The Roma ace made up for his mistake in the second half as he fired Italy back on track for them to earn a point as they drew 1-1 with Paraguay.
"It was a good game the way we played. We didn't give away much. On their first goal I was distracted as it was my responsibility to mark him, and we were angry, I was angry," he told Sky Sport Italia.
"They were aggressive and we were not that great in the final third and you pay for it at this level.
"Probably we have to improve in the final third, we have to be more concrete up there as we lack the final finish.
"We all have to continue growing, it's not about individuals improving, we have to improve as a team."
De Rossi was also highly critical of some of the player selections by coach Marcello Lippi, saying that the Azzurri are lacking a creative-type person such as Roma team-mate Francesco Totti.
"Sometimes you can win a match you can lose it, or you can end the match at 1-1 like today. We knew that Paraguay was a good team. It's very difficult when you play a South American team.
"We are a different team to 2006. We have no Totti and no players like him."
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