Defence coach Scott McLeod said Ennor had been sore for a couple of days, and his condition was acute appendicitis. He would be out of action for about five weeks.
No replacement had been selected, and McLeod said there were still options available to the selectors.
One player who empathised with Ennor was his Crusaders' teammate David Havili, now selected in the midfield after earlier Test matches at fullback.
Havili had been through similar frustration when requiring emergency surgery for a stomach problem. It had been a long road, he said, and much of it had been unclear when he would be able to come back, but he had been able to benefit from the Covid lockdown. It gave him the chance to recover and get his strength back.
"I'm extremely grateful to be back in this environment," he said.
“Sitting in a hospital bed I thought this day was never going to come. I had to put a lot of hard work to get back to where I needed to be.”
There were consultations with coaches about where he needed to play. His first goal was to play well for the Crusaders, and now it was to play well at international level.
He enjoyed playing in the midfield for the Crusaders this year and wants to carry that on.
Havili said it had been frustrating for Ennor after coming back from an ACL injury midway through the Super Rugby season, and appendicitis had come on quickly this week.
"He's all good now, he's had the surgery done and what I've heard is he's walking around and straight into recovery mode. It has been a bit unlucky for him. He's done so well to get back to where he had to be and to have that happen is really unfortunate," he said.
With midfield stocks reduced at the national level with Jack Goodhue, Anton Lienert-Brown and now Ennor unavailable due to injuries for the Steinlager Series, Havili said he was concentrating on learning as much as possible. He had been talking a lot with Lienert-Brown about the position.
While a more permanent placement in the midfield needed him to put on a little more weight, the skillset from fullback had helped him in playing the position.
McLeod said the community activities the squad were involved in while in South Auckland had been aimed at getting the team together. On the field, the week was about getting their structures and skillsets aligned and introducing the changes and tweaks to the way they wanted to play this year.
"We've seen a lot of changes in Super Rugby, so we like what we see in a bit of that, and we are going to adopt that into our game a bit as well," he said.
From a defensive standpoint, he said the continuity of play in Super Rugby was outstanding as the attack continued to develop.
He cited an example of the effects of that as the tight forwards having to read situations in games and call on specific skillsets under pressure and late.
"In the past, they wanted to be clear and decisive and give them one thing. They're having to develop there.
"In the back field, there are so many multi-options now that the attack can bring and [it was important] our back three being able to read all that and be in the right place at the right time," he said.
McLeod said he would be interested to watch the South Africa-British & Irish Lions and the Australia-France series' to see how northern hemisphere sides approached playing southern sides. And also how those southern teams played in response.