The Spanish side lost 1-0 in Portugal in the first leg, but former Real Madrid star Baptista feels the team have what it takes to turn the tie around.
"I think we’re more than capable of gaining the advantage on the scoreboard here at our home ground," he told reporters.
"We need to score a goal, but the important thing is being confident that it is possible. It’ll be tough, but we’re going to make things as hard as we can for Porto.
"We’ll make the difference with our attitude, game play and intensity. These factors will turn the result around from the first leg."
Manuel Pellegrini's side have never played a knockout match at home in Europe's premier club competition, and Brazil international Baptista believes the players will make it a night to remember for the supporters.
"This is an historic match for Malaga. We’re absolutely determined and full of positivity and motivation, as are the fans, ahead of tomorrow night’s game," he continued.
"The fans will really enjoy the match and we’ll be doing everything in our power to ensure we get the result we’re all hoping for."
The 31-year-old has been struggling with a thigh strain and was rated as a slight doubt for Wednesday's match, but he insisted he is ready to play a full part in the encounter.