Tyler Chatwood has been scratched from his scheduled start on Sunday against the Reds in Cincinnati, as his wife has gone into labor. Left-hander Mike Montgomery will start in his place.
The Cubs will likely need length out of Montgomery on Sunday after their bullpen compiled 5 2/3 innings in Saturday's 11-2 loss to the Reds, their third straight.
Montgomery has pitched well enough lately to warrant time in the rotation, particularly with Yu Darvish still on the disabled list. The Cubs are 12-11 in games Montgomery has pitched, and he has compiled a 3.11 ERA over 55 innings. He's gone six innings and given up just one run in each of his last four starts.
Chatwood has a 3.95 ERA over 68 1/3 innings in 14 starts this year.