Molina will start Monday's game against the Guardians, Thomas Harding of MLB.com reports.
With Austin Gomber (arm) scratched, Molina will step in for his first career MLB start. A Rule 5 pick by the Rockies last winter, Molina has pitched to a 7.56 ERA and 1.80 WHIP in nine appearances so far this season. He's maxed out at 3.2 innings in an outing, so this will now be a bullpen day for Colorado.