The Reds reinstated Gibaut (shoulder) from the 60-day injured list Tuesday and sent him outright to Triple-A Louisville.
Gibaut posted a 4.62 ERA and 1.34 WHIP across 25.1 regular-season innings this year before undergoing season-ending shoulder surgery in late August. He has enough service time necessary to reject his assignment and enter free agency, though it's unknown what his plans are.