Dallas Keuchel, ace of the first-place Houston Astros' pitching staff, is going on the 10-day disabled list.
Keuchel was scratched from his start Wednesday after coming off the DL last Friday.
He is said to be experiencing neck discomfort -- the same injury that has already interrupted his season.
The lefty is a Cy Young Award candidate and sports a 9-0 record with a 1.67 ERA in 11 starts this year.
In adjusting the roster, the Astros have brought up Francis Martes from their AAA farm club and moved starter Collin McHugh to the 60-day DL