Bin Hammam previously pledged to give the panel "convincing grounds" to clear him of allegations he conspired to pay Caribbean football leaders $40,000 cash bribes at a May 10 meeting in Trinidad.
"I am not confident that the hearing will be conducted in the manner any of us would like. It seems likely that FIFA has already made its decision weeks ago," he said in his statement Friday.
A verdict is expected Saturday, with bin Hammam facing a possible life ban from the sport.
The Qatari official said FIFA's case and evidence were "flimsy and will not stand up to scrutiny in any court of law." "Justice will eventually prevail whether through the FIFA ethics committee, the Court of Arbitration of Sport or if necessary, through other courts or legal proceedings in courts where we will be equal and no special privileges will be granted to either party," bin Hamman said.
It was unclear whether bin Hamman was attending the hearing in person or leaving his defense to his lawyers.
FIFA said it could not comment on which defendants and witnesses were present, in order to uphold the independence of the ethics committee.
Bin Hammam and two Caribbean Football Union staffers, Debbie Minguell and Jason Sylvester, face allegations of bribery conspiracy. Minguell and Sylvester did not attend initial ethics hearings in May and were not expected in Zurich this weekend.
FIFA dropped charges against vice president Jack Warner last month when he resigned all his football positions with a "presumption of innocence." Bin Hammam has criticized the integrity of FIFA's investigation and legal processes.
He claims the bribery case was politically motivated to stop him from challenging Blatter, who was at his FIFA office on Friday.
Bin Hammam has criticized FIFA's top administrator, Jerome Valcke, for his handling of a May 29 news conference immediately after the ethics court first met to weigh evidence and imposed provisional suspensions.
He later described secretary general Valcke's behavior as "absolutely unacceptable and against all principles of justice." Neither Blatter nor Valcke will be at FIFA on Saturday when the verdicts are delivered.
FIFA said Blatter would travel to Argentina to attend the Copa Americas final on Sunday, and Valcke was in Brazil ahead of the 2014 World Cup qualifying draw being conducted July 30.
Bin Hammam has also questioned why no Caribbean officials alleged to have pocketed bribes have yet been charged.
FIFA's ethics panel could call for new investigations into CFU members after it rules on bin Hammam's case.
