Heat general manager Andrew Blucher said he was gutted by Cricket South Africa's decision to withdraw permission for Steyn to play after it had granted it nearly six weeks ago.
Cricket Australia requested CSA re-consider their decision, but the Cobras insisted Steyn was required to play in a domestic one-day semi-final instead of the Gabba clash.
"We now find ourselves less than a week out from the opening game without a key element of our pre-game preparations and that is terribly disappointing for the team and our fans and members, who were eagerly anticipating seeing Dale play," Blucher said.
"Dale is also unhappy with this outcome.
"He and his manager are embarrassed and upset about the way things have turned out, considering we were crystal clear with what we had communicated to Cricket South Africa."
Blucher was fuming over their treatment after acting in "good faith" throughout their negotiations.
"We would have imagined that CSA and the Cobras would have consulted and worked out the various scenarios that would have been involved," he said.
"For that not to happen is quite extraordinary and highly unprofessional.
"But we will get on and give it our best shot from here."
Heat coach Darren Lehmann said he would scramble to seek a replacement international player by this weekend.
"We had a spot free so while it is quite late in the piece, we had looked at some contingency plans with a few players in the event we had something like this happen," he said.
"We'll get on the phone and email and see what is possible."
Vettori signed a three-year BBL deal with the Heat in July, having represented the franchise in last year's inaugural competition.
But he was ruled out for another six weeks after his Achilles complaint flared again.
"Despite his best efforts, he is highly unlikely to be ready in time for our BBL matches which is very unfortunate for him as we know how hard he has worked to be ready," Lehmann said.
-AAP
