كتب : Hatem Maher
The combative striker, who is on loan from Zamalek, infuriated Bruce after returning late from international duty following Egypt's draw with Zambia in the World Cup qualifiers.
Zaki, who sustained a hamstring injury against Zambia, did not give a clear explanation over his decision to stay in Egypt for about two weeks after the game.
He arrived in England on Thursday along with his advisors but will seemingly have to justify his actions if he is to prolong his stay at the JJB Stadium.
"It makes it (signing Zaki on a permanent basis) very difficult, I have to be honest," Bruce told Sky Sports News.
"It's not the first time we have had this situation, it's the fourth or fifth, and we have dealt with it before.
"But I find it totally unacceptable, the whole situation he has put the club into, and he has to have a bit of respect for the people who pay him.
"We don't even know how bad his injury is, it could be that he is out for the season anyway.
"We do know that he has got a hamstring problem and he has limped out of the last four minutes of the Egyptian game which was 11 or 12 days ago, but until we assess him and see how he is we will not know where we are up to."
Meeting
Bruce, who said last week that Zaki would be heavily fined, still wants to hear the 26-year-old's explanation before taking any action.
"We will meet him and his representatives in the next 24 hours and see where we go from there.
"I think the first thing to do is to speak to Amr and see where he is on all of this.
"I have made my point brutally clear of how disappointed I am with the whole situation. We are just saddened that it's turned out like this."