The Orioles made two roster moves ahead of Sunday’s series finale against the Washington Nationals, with one sending a player to the injured list and another casting a player off the roster entirely.

Baltimore designated right-hander Kyle Gibson for assignment one day after he allowed six runs in less than one inning.

And, for the second time since joining the Orioles over the winter, outfielder Tyler O’Neill is headed to the injured list. This will be his 16th career injured list designation, and it comes as a result of a left shoulder impingement.

O’Neill signed a three-year deal worth $49.5 million, although he has an opt-out clause he could activate after the first season. He has played 24 of Baltimore’s 44 games entering Sunday, and he hasn’t found consistency at the plate.

O’Neill is batting .188 with a .605 on-base-plus-slugging percentage. He was signed, in large part, to assist the Orioles against left-handed pitching. He has historically done well against southpaws, but in 25 plate appearances this year, he has two hits.

O’Neill got off to a roaring start as an Oriole. He hit an opening day home run for an MLB-record sixth time. But he has homered once since then.

The 29-year-old landed on the injured list earlier this season for neck inflammation. He said last month he tried to play through the malady but he had trouble turning his neck to the left.

“It’s not good for me; it’s not good for the team,” O’Neill said at the time. “Talking to the medical staff, we thought that it was best to just knock it out right now, hopefully come back on the minimum.”

It’s unclear whether O’Neill’s left shoulder impingement is related to his previous neck inflammation. He was a late scratch from the lineup Friday.

With O’Neill sidelined, outfielder Dylan Carlson was recalled. Carlson has been up and down between Triple-A Norfolk and Baltimore this year. He holds a .293 average in the minors but is hitless in 15 at-bats for the Orioles.

Gibson signed for $5.25 million during spring training, and he required buildup time before he was activated last month. But in four starts he posted a 16.78 ERA.

“I think these first two or three weeks have been frustrating to say the least,” Gibson said Saturday night. “Hard to find words really to go into it and to kind of voice it appropriately, honestly. Four times taking the mound feeling like you haven’t given the team a chance to win each time is a pretty big gut punch.”

To replace Gibson on the roster, Baltimore recalled right-hander Kade Strowd. He has yet to make his major league debut.

As O’Neill heads to the shelf for a minimum of 10 days, another Orioles outfielder is nearing a return.

Colton Cowser, who hadn’t spoken with the media since fracturing his thumb March 30, said he took batting practice on the field for the first time Saturday. He has been swinging the bat in lighter circumstances in recent weeks, however, and he has been working on his fielding in the outfield before games.

“We’re hoping to get into rehab games here soon and go from there, trying to get as many at-bats as I can and rehabbing and making sure that I’m feeling good to come back,” Cowser said.

Cowser said his head-first dive into first base — the play that resulted in his fractured thumb — early in the season was a result of instincts kicking in as he tried to avoid a tag from the pitcher covering first base.

“I know that it’s not a baseball play that you’re really supposed to make, but sometimes the instincts take over, and, hindsight, I could have just dogged it out of the box and not really put an effort in,” Cowser said. “But, at the time, was just trying to get the tying runner up to the plate. I’m always going to hustle; that’s just kind of who I am. Definitely, going forward, going to be definitely more cautious with that and be a little bit smarter.”

Because Cowser is on the 60-day injured list, he isn’t eligible to return until May 30. His return could provide a boost to a lineup that has underperformed. He finished second in AL Rookie of the Year voting last year after hitting .242 with a .768 OPS.