Flexen will start the first game of Monday's doubleheader against the Braves, Chris Bumbaca of MLB.com reports.
Flexen will rejoin the rotation for the first time since Sept. 3, when he was lit up for seven runs over four innings. The rookie has found his footing in the bullpen, allowing one run over five frames of relief, but his poor results as a starter earlier this season will make it difficult to depend on him as a streaming option Monday. Since he hasn't started in nearly three weeks, Flexen could be subjected to a limited pitch count in what's likely just a spot start.