Latics are second-bottom of the standings, above only QPR with 19 points, but Martinez - who has engineered Wigan's top-flight survival in the closing stages of the last two seasons - thinks this year will see a much tighter finish.
Historically, a 40-point target has been enough to secure Premier League status, but the Spaniard predicts that total could be a lot lower this year, with more teams fighting it out at the bottom.
Newcastle and Aston Villa are two sides hovering just above the relegation zone, while Fulham, Norwich and Southampton have by no means pulled clear.
"You look at the numbers and until you reach 40 points you haven't achieved your aim," Martinez said ahead of Tuesday night's clash with Stoke.
"You're looking at anyone from the 12th position down. It's going to be a really tight fight because you're looking at teams that are taking a bit of time to adapt to the division now they're ready, the newly promoted sides. It's going to be a very close final third of the season.
"Historically, 40 points is a measure of safety, but it could be a lot less than that. It's going to be a close fight because I do see teams that started at their best, but now they're not in a great position and others are beginning to find it difficult even though they are in a good position in the table.
"It's really open, probably more open than the table could suggest at this time."
Wigan travel to Stoke following their FA Cup win against Macclesfield before they host Southampton on Saturday.
It is a busy period for the injury-hit Latics, who are looking to find a replacement for defender Ivan Ramis, who is out until the end of the season with a cruciate ligament injury.
And Martinez, who claimed a 1-0 victory at Stoke on the last day of the season two years ago to avoid relegation, knows a tough task lies in store if he is to wrestle any points from Potters boss Tony Pulis.
"The Britannia Stadium is one of the hardest places to visit in the Premier League," Martinez said. "We know they have been in a difficult period with their results but they are still in a good position in the table.
"That is a sign of a team that is settled in the Barclays Premier League with a particular style which is always very difficult to play against.
"Stoke have found a way of playing and have got a real combination and they are very good at what they do.
"That's football. You need to be very good in what you do.
"Every time you see Stoke against Wigan they are open games with chances and goals and it is always good to watch. I don't expect anything different."