The injury could keep the right-hander out of action for at least two months.
Rosales first felt discomfort in the ankle on April 18, when he got the Padres' Kyle Blanks to ground into a double play. At the time, Rosales was pitching well and didn't want to go on the disabled list.
Instead, Rosales had the ankle wrapped by the training staff and tried to continue to pitch.
"He was getting better, but then he took a step back [Wednesday]," said D-backs manager A.J. Hinch, referring to pain Rosales felt during his outing against the Rockies.
The D-backs placed Rosales on the DL on Thursday.