Holmes will start the second game of Monday's doubleheader versus the Mets, David O'Brien of The Athletic reports.
He will sub in for Chris Sale -- who had to be scratched due to back spasms -- with a postseason berth on the line. Holmes made six starts and 19 relief appearances for Atlanta this season, posting a 3.78 ERA and 63:14 K:BB over 64.1 frames. His last start came on Sept. 22 when he went four innings and threw 62 pitches against the Marlins. Holmes also threw 1.2 innings and 21 pitches in a relief outing Sunday, so he will be quite limited in what he can offer length-wise Monday.