The Arizona Diamondbacks placed RHP Taijuan Walker on the Paternity Leave List and recalled RHP Matt Koch from Triple-A Reno. Walker, who was scheduled to be this afternoon's starting pitcher @ Reds, will be replaced by LHP Patrick Corbin.
 
Walker, 24, has left the team to be with his wife, Heather, for the birth of their first child.
 
Koch, 26, has gone 1-1 with a 8.47 ERA (16 ER in 17.0 IP) in 4 starts for the Aces this season. He made his Major League debut with Arizona in 2016, going 1-1 with a 2.00 ERA (4 ER in 18.0 IP) in 7 appearances (2 starts).