The Ghanaian midfielder is confident the San Siro side can still secure a top-two finish in the remaining six games this term
The Rossoneri were held to a 1-1 draw by the Partenopei in Sunday's encounter at the San Siro, but Muntari has stressed they will keep fighting to climb to second place.
"We still believe and we’ll be doing everything we can to get to second place. We’ll be fighting until the end of the campaign," Muntari told reporters.
"We did everything to win this game and it’s not over yet. Our aim is to get to second place. Our defence did well and the team is in good shape. I have faith.
"Now we have the match against Juventus. The game against Juve is a big one for us and we’ll try and do well. We know they’re a good team.
"We’re not scared of the teams behind us in the league."
Milan are trailing Napoli by four points with six more games to go.