Warner quit last month amid allegations he had facilitated the paying of bribes and FIFA dropped the investigation following his resignation. The world governing body did warn however that the investigation would be reopened if he were ever to return to football.
Warner, who had also been president of the CONCACAF organisation of countries from north and central America and the Caribbean, has said however he might do just that.
He told the Trinidad Guardian: "You can never tell what the future holds.
"There is some unfinished business which I will have to finish in both FIFA and CONCACAF at the appropriate time and who knows I may go back.
"The only expert on the FIFA in this country [Trinidad] is me and in the fullness of time I will tell this country what FIFA is and what FIFA is not."
Mohamed Bin Hammam, the 62-year-old Qatari who was Asian football president until his provisional suspension, faces a FIFA ethics committee hearing into the bribery allegations on July 22.
Meanwhile, Qatar's World Cup chief has claimed there is prejudice against his country's successful bid for the 2022 tournament.
Phaedra Al Majid, the so-called 'whistleblower' behind a series of bribery allegations involving FIFA members and the bid, has released a statement saying she fabricated all the claims.
Hassan Al Thawadi, general secretary of the supreme committee for the 2022 World Cup's general secretary, told BBC Sport: "The attack on 2022 fits the prejudice people have in their minds. An Arab nation could not have won.
Asked whether the Gulf state had paid money or gifts to secure the 2022 tournament he said: "We never broke any rules,"
Al Thawadi said calls for a review of the bid vote was an "absolute outrage".
He added: "If there is evidence, investigate the evidence, but if there is nothing there and it's based on rumours."