John Danks on 15-day DL
The move is retroactive to March 22.
Danks struggled with velocity issues on Sunday while facing White Sox minor leaguers, yielding four home runs in fewer than four innings of work. His fastball topped out at 86 mph.
"I am just getting work in," he said Sunday. "This is just a part of the process of working up arm strength and trying to make pitches do what you want them to do.
"(Velocity) will come. The good thing is that I keep getting out there every five days. I feel like I am making strides to get where I want to be."
Danks will fly with the team to Chicago for Monday's Opening Day and return to Arizona on Tuesday before pitching on Wednesday.
Right-hander Dylan Axelrod will pitch in the fifth spot in the rotation.
It also appears Sox outfielder Alex Rios will miss the final two Cactus League games with lower back pain that kept him out of the previous three games. Rios played for Puerto Rico in the WBC and returned to the Sox on March 22. He said he'll try to play in one of the exhibition games in Milwaukee this weekend.
"It is not something that we have to worry about," he said. "It is just going to take time to heal.
"I felt better this morning but on certain moves I still feel a little pinch there. I had pretty decent progress from yesterday until today. I feel looser, let's see what happens."
ESPNChicago.com's Bruce Levine contributed to this story.