"It wasn't what they wanted to see," Norris said of the MRI results.
"It's kind of frustrating because I've been throwing the ball so well and obviously I want to keep playing, but I've got to get this thing right. We still have a lot of season left, we're not even at the [All-Star] break yet, so hopefully I can just let this thing calm down, get back to 100 percent and get back out there."
Norris is 7-5 with a 3.62 ERA in 14 starts and has allowed two runs over his last 19 2/3 innings. He was placed on the 15-day DL retroactive to Sunday and could return July 7 when the Orioles begin a two-game series in Washington.
"We're trying to get into a stretch and reel off a lot of wins, so that's the frustrating part, but these guys are going to pick me up and I'm going to pick them up when I get back," said Norris, who has been instructed to take five days off completely to let the groin heal.
"I want to do my job, I want to pitch every fifth day and win as many ballgames as I can and stay healthy. So I'm a little bummed out about it, but I've got to care of it and get back as soon as I can."
The Orioles recalled right-hander Evan Meek from Triple-A Norfolk to take Norris' spot on the 25-man roster. Meek is 0-2 with a 6.39 ERA in 12 2/3 innings over 13 appearances with the O's. The 31-year-old has gone 2-0 with a 2.79 ERA and three saves in 17 games for Norfolk.
While Meek joins the 25-man roster, the Orioles also officially called up right-hander Kevin Gausman from Norfolk to serve as the 26th player on the roster for Friday's doubleheader.
Gausman, who started Game 1 against Tampa Bay, has been excellent in four starts, going 3-1 with a 2.74 ERA and 1.17 WHIP. Per MLB rules, Gausman will return to Norfolk after Friday's second game of the doubleheader.
Chris Tillman will start Game 2 on Friday, with Wei-Yin Chen expected to start Saturday and Miguel Gonzalez on Sunday.
Ubaldo Jimenez could start Monday on regular rest in the opener of a four-game series against the Rangers.
Manager Buck Showalter suggested that Tuesday's start could go to right-hander T.J. McFarland, who is 0-1 in 13 relief appearances with a 2.81 ERA. Showalter said that the team may also look to Norfolk or Double-A Bowie for an emergency starter. He ruled out the possibility of Gausman starting on three days' rest.
"In June or [early] July, I wouldn't do that," Showalter said. "I don't think that's smart. It's not fair to him or to the team or to the fans. I think that would put him in harm's way.
"Right now, we're probably looking for a break in the weather… But we'll be all right. We've got some good options. That's where you were kind of hoping that a guy like Johan [Santana] would fit in. [Randy] Wolf isn't there yet."