"It was obviously a wrong decision," New Zealand coach Tony Readings told the Herald today.
"I don't think there's any debate if the wrong or right decision so we're looking now at the appeals process. We've got a legal team looking at it in New Zealand as well."
New Zealand, ranked 17th, were worth the win against their 24th-ranked opponents, but had to survive a late scare when goalkeeper Erin Nayler pulled off a fine, one-handed save to her right from the freekick resulting from Erceg's dismissal.
With Ferns' minds racing as Erceg headed for the tunnel, but Nayler did a top job.
"Amber Hearn's goal won the game but that save played just as important a part," Readings said.
Hearn scored after half an hour, wrongfooting the Colombian goalkeeper and apart from a late flurry from the South Americans were worth the win.
"Fingers crossed justice prevails," Readings said. "Referees are going to make mistakes and there needs to be a way to overturn them.
"Abby's been outstanding in these first two games (New Zealand lost 2-0 to world No 1 United States in their opener) and to get an incorrect decision that would have us not at full strength is going to be pretty tough. We do have good players to step in but it's very hard to replace that experience and your leader."
Readings said his players had taken Erceg's fate reasonably well.
"We've put ourselves in a position that if we win the next game we'll finish second so we're really upbeat about that."
The Football Ferns play France in Salvador on Wednesday morning (NZT). It'll be a daunting enough task, even with the seasoned Erceg running the cutter.
The last time the teams met, late in 2014, France won 2-1 but the challenge for the Football Ferns is the state of the three groups.
The top two in each group automatically progress to the last eight, along with the best two of the three third-place finishers.
Brazil, Sweden and China are all expected to progress from group E while Australia, on one point, are the strongest of chances to topple bottom placed Zimbabwe in group F, which would put them on four points, either level with Germany or in second spot behind Canada.
Therefore, with a goal difference of -1, New Zealand really need a win over the French.