He insists he "doesn't care" whether outsiders doubt his team's ability to claw back nine points on current fourth-placed side Manchester City.
Martinez said: "The reality is we want to be demanding of each other - challenging for the top four and against anyone. If it's realistic or not I don't really care.
"I'll never hide from the desire of wanting to be successful because we've got a team with the potential to do that.
"Experience in big games is a big part of becoming a winning team. That's normal. Away at Arsenal it went down to small margins and key moments in the game.
"We're not far away from where we should be, but it's just about developing that experience of knowing what to expect.
"Playing well is important as a team but in terms of becoming a winning team you need a bit more understanding of what is needed to get those results."