"In the first game they pressed us pretty high and we found it hard to break down their pressure and it allowed them to gather momentum.
"Whereas today we were a lot more assured in possession, we moved the ball really quickly and it didn't enable them to get the pressure on the ball."
"So we enjoyed a lot more possession than they did in this game but unfortunately for us we weren't able to convert that into goals.
"We created a lot of good half chances, sometimes that's all you're going to get when you play against good quality opposition. The best teams in the world can convert those chances and today we weren't able to do that."
With time winding down, the Ferns kept chasing a winner and Nayler was forced into a couple of good saves but Readings says that brave attitude is something they want to continue to encourage against the world's best.
"We were pushing forward for a goal at the end because we wanted to win the game and they caught us on the counter attack a couple of times. That's something we've got to mindful of moving forward."
Summing up the tour, Readings says the two games have been another valuable learning experience for the team with the FIFA Women's World Cup coming in June.
"We weren't so good in the first half of the first game, we were good in the second half and we were good across the whole game today."
"Overall it's been quite a solid tour for us and we think definitely a step forward because today we've kept a very strong Spain team goalless. But at the same time we haven't scored and we know it's something we need to work on but it's the first time it's happened this year."
Meanwhile, Friday's match marked the 100th senior international appearance for Football Ferns midfielder Katie Hoyle as she joined captain Abby Erceg and Ria Percival as the third member - male or female - of the New Zealand Football 100 club.
In typical fashion, Hoyle focussed on the team as she described her feelings on reaching the milestone.
"It's pretty awesome to reach 100 caps," Hoyle said, "but obviously we would have loved to seal it with a win but we're happy with our performance today.
"[It was] improved from the last game and we had them under pressure a lot in the game and we were unlucky really not to get a goal in the back of the net."
The next match in the Football Ferns FIFA Women's World Cup build-up is against world number two the United States in St Louis on Sunday 5 April (NZ time).
Spain 0-0 Football Ferns (half: 0-0)
Spain 0-0 Football Ferns (half: 0-0)