A fourth executive, the former FIFA vice president Chung Mong-joon, was barred from the sport for six years on Thursday and fined 100,000 Swiss francs, or about $103,000. Mr. Chung, a South Korean billionaire whose family heads the Hyundai conglomerate, had, like Mr. Platini, been a candidate to replace Mr. Blatter in a February special election. But he was found to have violated FIFA’s ethics code in connection with the bidding processes for the 2018 and 2022 World Cups, FIFA said.

Mr. Platini, who had been seen as the favorite to replace Mr. Blatter, filed paperwork Thursday morning to officially become a candidate for president, but it was unclear whether he would be permitted to run.

The suspensions for Mr. Blatter, Mr. Platini and Mr. Valcke can be renewed for an additional 45 days after the initial 90, and it was believed that they would require a complete separation from FIFA. In a statement, FIFA said Mr. Blatter “is not allowed to represent FIFA in any capacity, act on the organization’s behalf, or communicate to media or other stakeholders as a FIFA representative.” According to a person close to Mr. Blatter, he may dispute whether that prohibits him from going to his office each day. The title of FIFA president was quietly removed from his Twitter account.

Mr. Platini pushed back too, releasing a statement through UEFA, in apparent violation of his suspension hours earlier from “all football activities on a national and international level.” In the statement, he dismissed the allegations against him as “astonishingly vague” and the process that led to his ban as “farcical.”

“I am driven by a profound feeling of staunch defiance,” he said. “I am more determined than ever to defend myself before the relevant judicial bodies.”

UEFA’s executive committee also defied the FIFA suspension, announcing in its own statement that it would not invoke rules of succession in its leadership — effectively leaving Mr. Platini in place as UEFA president. It later clarified that Mr. Platini would not perform his official duties or attend meetings, but it did not name an acting president.