Latics take on Premier League champions Chelsea on Saturday, still licking their wounds from an opening day humiliation at the hands of Blackpool.
Martinez's men were soundly beaten 4-0 by the top-flight new-boys on their home patch last weekend, and the manager will now be looking for a response from his side.
However, the Blues smashed Wigan 8-0 on the final day of the last campaign and next week Latics travel to Tottenham - the scene of their infamous 9-1 defeat last term.
Martinez has the backing of chairman Dave Whelan and insists that even if his team lose all three games comfortably, he will not fear the chop
"The sack does not worry me," he told the Daily Express. "I don't think you can approach any job in football, in life even, with fear.
"The moment you do that you are going to fail.
"Whatever people think or say, your approach to your job has to be perfect. That is all you can control."
The Spanish coach believes that he will be judged on the team's standing next May rather than in the first month of the season.
"Halfway through the season is when we need to assess how well we have gelled and how the season is going," he added.
"It does not bother me after three games where we are going to be in the table.
"What interests me is the level of performance of the team and where we are going to be in the table in the second week in May."