"As soon as I got hit, I thought 'why didn't I hit it?'
"Then when I was trying to get the ball out of my helmet [it had lodged between the peak and top of the grill] my conscious thought was 'can I see?'
"The impact was above the eye and we've seen a few cases where people haven't made a comeback from that."
The 29-year-old has received encouraging medical advice, firstly that he can start light exercise in a couple of days then, with luck, be bowling in the nets in about a week.
He'll have to get used to a newer model of helmet, with a narrower gap. McClenaghan knows the key moment will be how he handles the next short-pitched flier when the brain may send messages he mightn't fancy hearing.
"When it comes to batting, the boys will tell you I'm pretty confident throwing the willow around. I know it's going to be hard. The brain works in funny ways in letting you do these things but I'm pretty confident I can overcome them."
He was chuffed to see the quality of New Zealand's bowling display in the 159-run beating of Australia at Eden Park on Wednesday night.
"It was just phenomenal to see how the guys are stepping up."
The clock is now ticking for the lively left armer with the world T20 coming up. More importantly, he's come through a physical injury which could have been disastrous.
"I haven't even looked at it yet," he said of the bashed-in helmet, which is still sitting in his bag at Eden Park.
"It might be one of those things you put up on the mantelpiece as a constant reminder of, A: how much it hurt and, B: how lucky I am to be able to come back and play this game again."