A corresponding roster move may not come until Tuesday, following another open date on the Orioles' schedule. They most likely will go with 24 players in Sunday's series finale against the Royals.
Davis left Friday night's game after four innings due to the injury. He hoped to return to the lineup in a couple of days.
"A little bit worse than what we thought it was going to be," he said following tonight's 3-2, 10-inning win. "Strain, I guess is what we're calling it. Obviously, the oblique. It's kind of crazy because I don't feel terrible. I've never had anything like this before. I figured it would just be a few days and then we'd forget about it."
Davis doesn't know the grade of the strain.
"Not terrible but it's not great," he said. "I could obviously feel it last night. I was pretty sore today and having the MRI results and everything, I guess the DL is the best choice right now. From everybody I've talked to, basically what they've said is it's just something that could be a lot worse if you neglect it. For right now, just keep it simple and hopefully, like I said, be back soon.
"As far as I know right now it's 15-day DL, so hopefully things will go well and I'll be able to bounce back quickly."
Davis is batting .250 with four doubles, two homers and 13 RBIs in 22 games this season. He was named Most Valuable Oriole in 2013 after leading the majors with 53 homers, 96 extra-base hits and 370 total bases. He also made his first All-Star team and won his first Silver Slugger Award.
"It's definitely disappointing, frustrating," he said. "I do a lot to try and take care of my body and prevent injuries. You play this game long enough, eventually you're going to run into something like this, but I'm going to stay positive.
"I definitely have the best group of guys behind me and they picked me up tonight with a win and an exciting win. That was good to see. We've got more than our share of guys in here that are capable of picking me up and (helping) the team until get back."
Davis said he'll stay with the team and perhaps travel, instead of reporting to the minor league complex in Sarasota.
"I want to be around as much as I can," he said.
"We're gonna do the same treatment I've been doing the last couple of days. I think the biggest thing right now is rest. Not trying to go out there and do too much, From what Ive heard, it's a lot like a hamstring. You might feel good, but it might not be right there. Just be patient with it. A small obstacle right now."
Nick Markakis, who drove in the winning run tonight, figures to get most of the starts for Davis at first base. The Orioles could recall Henry Urrutia from Triple-A Norfolk as an extra outfielder and designated hitter or go back to a 13-man pitching staff.
Manager Buck Showalter wouldn't offer details of the MRI result.
"I know specifically, but I'm not going to share. I appreciate you asking," he said.
"It's something we think will take the DL period at a minimum, so we'll start with that tomorrow. That doesn't mean we have to bring anybody. We could wait a day with the off-day. We'll see. I'm not sure what they've decided yet. The off-day puts a little different dynamic with it."