Back in Europe’s premier club competition for the first time since the 2013/2014, AC Milan have failed to win any of their opening three group stage games.
Stefano Pioli’s men followed losses to Liverpool and Atletico Madrid with a 1-0 defeat away at FC Porto on Tuesday.
The Rossoneri now have a herculean task of progressing past the group stages as they sit bottom of Group B, four points adrift of Porto in third with three games to go.
Ibrahimovic could not inspire Milan to victory after coming on as a second half substitute, but the 40-year-old is adamant all is not over for his side.
"Today was our worst match in the Champions League," said Ibrahimovic. "Unfortunately we are still on zero points after three games.
"We must remember that this team is back in the Champions League after so many years and games like this will give experience to the whole group."
Speaking to Mediaset Canale 5, he added: "Players were missing, but this is part of football. I just got back and I'm happy to play."
"I don't want to find excuses. In the next match we have to do better. There are three games left and, as long as there is a chance, we will try. I am confident."