Speaking to Entertainment Weekly, Stephen Nathan admitted that he does not expect Millegan to return to the show.
"We love Eric and would like him to return," he said. "But we have no immediate plans yet. Of course, it's always about juggling schedules now that Eric is back in NYC and busy entertaining the masses in the Big Apple."
However, he added: "The season is young and it remains a possibility."
Bones returns for a new season on September 23 on Fox.