The Frenchman, whose job was to ensure the smooth running of FIFA, and in particular the World Cup, was right-hand man to now banned president Sepp Blatter before both were embroiled in a corruption scandal which swept soccer's governing body in 2015 and led to a significant change in leadership.
Valcke was found guilty by FIFA's former ethics judge Hans-Joachim Eckert of misconduct over the sale of World Cup tickets, abuse of travel expenses, attempting to sell TV rights below their market value and destruction of evidence.
After being sacked from his post in January 2016, he was initially banned for 12 years, which was reduced to 10 by FIFA's own appeal committee last June. He has denied wrongdoing and is now appealing at the Court of Arbitration for Sport (CAS).
"It takes years to create your reputation, it needs one second to destroy, that's where I am," he told reporters. "I am living in peace with my family, I remain strong in my world and that is what I protect."
He said the hearing was "difficult".
"You have to be very clear with your statements," he said. "I hope that the panel of the CAS will have got my point of view.
"I often ask the question to myself, why such a desire from FIFA to destroy not only what has been done in the past and what has been done by myself?"
Valcke, who has resettled near Barcelona, is still facing criminal proceedings in Switzerland.
In March last year, the office of Swiss attorney-general Michael Lauber said Valcke was suspected of criminal mismanagement and other offences. He denies any wrongdoing.
Valcke joined FIFA in 2003 as marketing director but was fired in December 2006 for his part in botched sponsorship negotiations with credit card firms MasterCard Inc and Visa Inc.
Within months of that settlement, Valcke was not only back at FIFA but was at the helm of the administration as secretary general, answering directly to Blatter.
He was widely credited with getting the 2010 and 2014 World Cup tournaments, held in South Africa and Brazil respectively, up and running in time after delays in the preparations.
(Reporting by Simon Evans; Editing by Christian Radnedge)
