The 31-year-old is nearing a return to full fitness after overcoming a hip injury, and says the Latics squad are optimistic ahead of their final four games of the season
Roberto Mancini’s side are five points adrift of safety with four games left to play, but have a match in hand on their rivals.
"We're looking at every game between now and the end of the season as one we have to win, and we believe we can do that," Caldwell told the Wigan Evening Post.
"We've been down there and managed to get out of it for the last few years, and we're bracing ourselves for it going all the way again.
"It's in our hands, and we have to have a real belief that we can still get out of it."
Caldwell has been out of action since the beginning of April with a recurrence of a hip injury, but is now nearing a full fitness.
And with Antolin Alcaraz joining the injured duo of Maynor Figueroa and Ivan Ramis on the treatment table recently, Martinez will welcome the return of the centre-back.
"All you can do when you're out of the team is keep working hard and being ready for when the opportunity arises again," Caldwell continued.
"Everyone in this squad has a massive role to play between now and the end of the season.
"Everyone has to be ready for when the gaffer decides it's right to go in, and that's definitely the case with me."