The Astros announced that Brett Oberholtzer, Josh Fields and Brad Peacock will all start the season on the 15-day disabled list, according to the Houston Chronicle.
Oberholtzer is dealing with a blister on his left index finger, and will have his DL stint backdated to March 31.
"It's a blister. It's not an arm injury," Oberholtzer said. "I just have to wait until the skin heals and take a little time and get back at it. ... I'm just day to day right how, obviously. I'll just wait until the skin heals up and gets right and allows me to make pitches comfortably and not deal with any side effects from the skin."
Fields is working his way back from a groin injury, and will have his DL stint backdated to March 27.
"I was trying to push it pretty hard, but I felt like I was going about it in a wise way," Fields said. "I made pretty quick progress. The fact that they've laid something out for me like that I think is going to help of 'OK, I can relax. I have a plan now of when I'm supposed to be back and just make sure everything is good and right.'"
Peacock, who is recovering from offseason hip surgery, will start the first game of the season at Triple-A Fresno, per MLB.com. His DL will be backdated to March 30.