Mikolas was reinstated from the paternity list prior to his start against the Cubs on Sunday, Derrick Goold of the St. Louis Post-Dispatch reports.
Mikolas will rejoin the club after being away from the team for the past few days due to the birth of his child. Through 19 starts this year, Mikolas is sporting a 2.79 ERA and 1.05 WHIP with a 6.3 K/9.