Despite targeting all three points against the Belgians, Manchester United midfielder Fletcher has admitted that it would still be a tall order for his nation to reach their first World Cup since 1998.
"We need a massive result on Tuesday night," he said. "There is no doubt about it.
"If we can win that, it would still be an uphill battle but we need to regroup quickly, get our good game plan ready for Belgium and if we can go there and manage to get three points then we will be slightly back in it. That is going to be a big ask."
Fletcher recently returned to the national team following a 12-month battle with a bowel condition.