The bizarre and disturbing injury saw Mackenzie knocked out before he hit the ground after being belted by a close-range kick from Rhys Stanley.
It was a low point in an otherwise great night for West Coast, who beat the Saints by 33 points to reach just the second pre-season grand final in the club’s history.
And the good news kept coming with Mackenzie unperturbed by his momentary knockout and in contention to take on the Crows at AAMI Stadium next Saturday night.
“From all accounts he was only … dazed for a couple of seconds, the medicos wanted to check him out. He looked alright in the team meeting," coach John Worsfold said.
“I reckon it has happened before … it was pretty flush full on hit.
“But a footy hitting you like that is a lot better than a bash onto the ground or a head clash.
“A footy would be my preferred choice, if I had one.
“It was one of those ones you grimace at.
“My expectation is that he will be fine, the word was he did not show any signs of concussion.”
Dean Cox was the star as the Eagles dominated an almost full strength Saints side who still looked well short of top fitness ahead of their round one clash with Port Adelaide.
“We're desperately in need of getting some match conditioning in and I think that showed,” Saints coach Scott Watters said.
“We probably weren't as clean around the contest as we would've liked. We were outrun between the arcs tonight by a side that looked a little bit more match conditioned. It was a start for us and we really needed it to assess where we're at.
“There's a reality to that performance and the reality is we need to improve.”
Worsfold will regain several top line players, including Andrew Embley, and Darren Glass, with Andrew Gaff, Luke Shuey and possibly Josh Kennedy all a chance.
“All the boys who came in for their first hitouts, Waters and Naitanui and those boys - they all looked sharp,” Worsfold said,
“It also gives us confidence that if Kennedy or Shuey or Lynch don’t play again this pre-season, that we are really confident they will come in and play well in the first game of the season.
“Overall the Saints had a good team in, and to match them was impressive by the group.”