The punk pop group have been on an indefinite hiatus since last month, with Wentz blaming burn-out.
"We lived and ate and slept and breathed Fall Out Boy for seven years," Wentz said.
"We never had a break for longer than two months.
"And that compresses you, and it compresses your creativity. I think taking a break could allow that to come back, really."
Bassist Wentz said he wanted to assure his Australian fans that he and bandmates Patrick Stump, Joe Trohman and Andy Hurley, weren't saying goodbye forever, despite rumours to the contrary.