BALTIMORE—The Orioles placed Alex Cob on the 10-day injured list for the second time this season on Tuesday. The 31-year-old right-hander, who began the season on the injured list because of a sore right groin, was put back on the list because of a lumbar strain — five days after pitching in the Orioles’ home opener.

Cobb was placed on the IL retroactive to April 6.

The Orioles have not announced a starter for Wednesday’s game against Oakland, which Cobb was scheduled to start. Josh Rogers, who was listed as the starter for Triple-A Norfolk in the first game of a doubleheader in Charlotte, was scratched.

Cobb was named the Orioles’ Opening Day starter but suffered a groin injury and was placed on the IL to begin the season. In his only start, Cobb allowed two runs on five hits in 5 2/3 innings in the Orioles’ home opener against the New York Yankees.

Earlier in the day, the Orioles put right-hander Nate Karns on the 10-day IL because of a strained right forearm and recalled right-hander Evan Phillips from Norfolk.

Karns, who hadn’t pitched in the major leagues for nearly two years because of injuries, has allowed one unearned run in 5 1/3 innings on seven hits.

He’s pitched in four games, two as the opener, and two in relief. Karns said he felt tightness but no pain.

“It wasn’t a one-day thing,” Karns said. “It was something where my velocity was dipping down. It kind of spooked some guys. We felt it was best to give it 10 days now and get back out there instead of it going in the direction we didn’t want it to go.”

Karns said he would remain with the team instead of going to Sarasota, Fla., for rehab.

“Last year, I couldn’t pitch in a game,” Karns said. “This is just a minor setback. We feel like if we can squash it will be better off in the long run…With the velocity trending downwards from the beginning of the season, we want to give it 10 days to get back to where it’s going to be productive.”

Manager Brandon Hyde said he wanted to be conservative with Karns.

“He just hasn’t pitched in a long time,” he said. “It’s been a couple of years. He’s coming off something that put him on the shelf for an extended time. There’s times during the season where you give yourself a breather, let the arm heal, not throw for a few days. Hopefully, he’s going to respond, and be good to go and be ready to throw in 10 days or so.”

Phillips, who pitched a scoreless 9 2/3 innings in spring training before being sent to the Tides, found out about his promotion while watching the NCAA championship game on Monday night.

He threw 1 2/3 scoreless innings for Norfolk and handled his demotion well.

“I wasn’t surprised at all,” Phillips said. “I wasn’t worried about making the team or not making the team. I was worried about how I was pitching, how I was feeling, and I thought I did both those things well. I came out of spring training healthy. I took it down with me to Triple-A, had a good couple of innings down there and, hopefully ,keep that going up here.”