When someone at the rally yelled "Blatter!", Warner said: "And why is it he ain't charged?"
Warner was arrested on Wednesday, hours after US prosecutors claimed he accepted bribes during the campaigns to host the 1998 and 2010 World Cups, won by France and South Africa respectively.
He faces 12 charges, including conspiracy to defraud and engage in racketeering.
The Trinidadian's name was on a list of nine current or former Fifa officials and five business executives who "abused their positions of trust to acquire millions of dollars in bribes and kickbacks", according to Loretta Lynch, the US attorney general.
After initially protesting his innocence on Facebook, Warner later surrendered to authorities in Trinidad and Tobago and appeared in a Port of Spain court before a judge who set his bail at $394,000 (pounds 258,000). US authorities alleged that Warner had harnessed his power at the highest levels of football administration as far back as the early-90s for personal gain.
Part of the lengthy indictment reads: "Among other things, Warner began to solicit and accept bribes in connection with his official duties, including the selection of the host nation for the World Cups held in 1998 and 2010, which he participated in as a member of the Fifa executive committee."
Warner, who left Fifa in 2011 after being suspended by an ethics committee looking into corruption, was also president of the Confederation of North, Central American and Caribbean Association Football (Concacaf) and a special adviser to the Trinidad and Tobago Football Federation (TTFF).
This week he denied any wrongdoing, saying he was no longer involved in global football administration.
He said the timing of the revelation of the US indictments - two days before a Fifa presidential election that could keep the embattled Blatter in control - was noteworthy.
"The actions of Fifa no longer concern me," Warner said in a statement.
"I cannot help but note, however, that these cross-border coordinated actions come at a time when Fifa is assembled for elections to select a president who is universally disliked by the international community."
Blatter survives corruption smear
In the end, nothing could stop Sepp Blatter.
Not a far-reaching corruption scandal. Not a tarnished international image. Not a young prince who gave him a stronger-than-expected challenge.
Despite the biggest crisis in Fifa's 111-year history, Blatter emerged victorious once again yesterday, winning re-election as president of world soccer's governing body for a fifth term.
"I am now the president of everybody," the 79-year-old Blatter crowed after defeating Prince Ali bin al-Hussein of Jordan to secure another four years in office as one of the most powerful men in sport.
Blatter was declared the victor after Prince Ali, 39, withdrew after the first round of secret balloting among Fifa's 209 member federations. Blatter won the first ballot 133-73, only seven votes short of the two-thirds majority required for victory.
Blatter has refused to step down amid US and Swiss corruption investigations.
"I am not perfect, nobody is perfect, but we will do a good job together I am sure."
The election took place two days after seven football officials were arrested in dawn raids at a luxury Zurich hotel.
The US Justice Department indicted 14 people on charges of bribery, racketeering, money-laundering and other charges.
In a separate investigation, Swiss authorities are looking into Fifa's awarding of the 2018 World Cup to Russia and the 2022 tournament to Qatar.
And Britain's Serious Fraud Office said yesterday it is assessing "material in its possession" relating to allegations of Fifa corruption.
Blatter himself was not implicated in the US indictments, but prosecutors have said the investigations are far from over.
Blatter, who has been in office for 17 years, portrayed himself as the man who can guide Fifa through the tumult and restore trust in an organisation that has been left reeling from years of corruption accusations.
