The 36-year-old midfielder said in an exclusive interview with Athenian radio station NovaSport FM that he talked with AEK officials and that they gave the okay for him to join Bunyodkor, even though the Brazilian star has one more season on his two-year contract with the Greek team.
"I ask forgiveness from AEK supporters, but you can't say no to such a proposal," Rivaldo told the radio station. "It has been a tough day. I had to make a very difficult decision. Something very positive has come up late in my career and I cannot turn it down."
Rivaldo has played the last four seasons in Greece, three for champions Olympiakos Piraeus and after refusing to accept a pay cut with them for a fourth season, he joined AEK.
He added that he was pleased with AEK and had no problems with the club: "It's just that things happened fast and I had to go. Anyone else in my position would not have said no to such a deal."
Rivaldo did not reveal to the radio station the financial deal with Bunyodkor, but noted it was the same team, then known as PFC Kuruvchi, that made a 30 million dollar offer to Barcelona striker Samuel Eto'o last month.
He said with AEK he ended his contract by mutual agreement and that neither side owes compensation.