WEST PALM BEACH, Fla. -- The Nationals’ Opening Day roster is starting to take shape after their latest and most extensive round of cuts following Saturday’s 4-4 tie with the Cardinals. Washington trimmed the roster in camp down to 30 players, including three players who seem almost certain to begin the season on the injured list.

Joe Ross was optioned to Triple-A Fresno, Erick Fedde and Spencer Kieboom sent to Double-A Harrisburg, while Carter Kieboom, Henderson Alvarez III, Aaron Barrett, Scott Copeland and Vidal Nuno III were all re-assigned to Minor League camp. Earlier in the day, catcher Pedro Severino was claimed off waivers by the Orioles, ending his career with the organization that signed him from the Dominican Republic in 2010.

One slot remains open in the bullpen and two on the bench with Howie Kendrick (left hamstring), Michael A. Taylor (left knee/hip) and Koda Glover (forearm) all likely to begin the season on the injured list. Right-handers Wander Suero and Austen Williams remain in camp to compete for the final bullpen slots while Andrew Stevenson, Adrian Sanchez and Jake Noll remain in camp for the final bench slots. The Nats have not committed to the usual seven relievers and five bench players, so perhaps they could decide to keep an extra arm in the bullpen and play with a short bench until Kendrick returns.

Suero began camp as the favorite to secure the final bullpen slot, but Williams has entered himself into the conversation after a fantastic spring, where he retired 23 of the 25 batters he faced, striking out seven batters in 7 2/3 innings without issuing a walk or allowing a run.

Stevenson seems almost certain to make the roster as the fourth outfielder in place of Taylor. And the Nats could decide to keep Sanchez, who has bounced around the field as the team aims to convert him into a super-utility player or Noll, who has put together an impressive spring at the plate (.326/.408/.558 in 49 plate appearances) to remain in camp this deep into spring.

Martinez on Kieboom: “it’s just a matter of time”
Manager Dave Martinez was also impressed with what he saw from Kieboom, the team’s No. 2 prospect and 25th overall in baseball as rated by MLB Pipeline, in his first big league camp. He played in 24 games and finished batting .300 with a .975 OPS. There are still some adjustments to be made playing second base, and Martinez noted they want him to be more fluid turning double plays, but he seems on the doorstep of earning a Major League callup.

“He’s going to be really good, he really is,” Martinez said. “His hitting, he impressed all of us, his ability to just understand the game at his age is pretty good. He understands what he needs to do. He doesn’t have to be told to hit the ball the other way or get guys over, he does it. Asking him to go over and play second base and he did it kind of naturally. I mean, he still needs a lot of work on turning double plays from that side, but he looked comfortable, and he started getting actually better the more he played over there. For me, it’s just a matter of time before you see Carter Kieboom helping us in the big leagues."

Severino’s tenure ends
Severino’s days in D.C. had been numbered since the Nationals went out and invested in a pair of catchers this offseason, acquiring Yan Gomes in a trade from the Indians and signing Kurt Suzuki in free agency. That left no place on the 25-man roster for Severino, who was also out of options.

The Nats had hoped Severino, 25, was ready to grab the starting catching job last season, but he never hit consistently enough to justify frequent playing time. He appeared in parts of four seasons in the Majors, which includes a two-game stint in 2015, but batted just .187/.273/.287 and a 48 OPS+. Even his strong defensive metrics, a strong throwing arm (84.3 mph on throws last season, 12th best in the Majors, per Statcast) with respectable pitch-framing numbers were not enough to continue earning playing time.

“Just consistency, that was the biggest thing,” Martinez said. “I know we talk a lot about catching, calling games and things like that. My concern wasn’t about his hitting, it was more or less about when he didn’t hit the inconsistencies of his catching started going the other way. But he came into Spring Training and he worked and he looked really good, but I assumed when the time came, somebody was going to see what we saw and they did."

Worth noting
• Ross will start the other half of Sunday’s split-squad games against the Mets. Afterward, he will head to Fresno to get stretched out as a starting pitcher as the Nats begin to build his innings for the season. However, the team wanted to keep Fedde and Spencer Kieboom in Harrisburg to have a pitcher and catcher much closer to D.C. if an injury occurs and they need a quick callup.

• Nuno had an opt-out clause in his contract but decided to accept the invitation to Minor League camp instead. His demotion is also an indication the Nats expect left-hander Tony Sipp to be ready for Opening Day after joining camp late.

• Martinez also raved about what he saw from Barrett, pitching in his first big league games since 2015, even if it was only Spring Training after a plethora of injuries have robbed him of the past few seasons of his career.

“He’s been unbelievable,” Martinez said. “Besides the story itself, just getting to know the person, it’s just incredible to see. Here’s a guy that everybody thought was out of baseball and he’s thrown -- he was worried about his velo and all of a sudden, throwing 93 again. He couldn’t throw slider very well, now the slider is almost about where it used to be. So, for him, it’s continue to build his strength and I really believe somewhere along the line he’s going to help us.”

• Alvarez will also be built up as a starter in the Minors.

Up next
The Nationals wrap up their Grapefruit League schedule with a pair of split-squad games. Ross will start in Port St. Lucie against the Mets at 12:10 p.m. ET Sunday, while Patrick Corbin starts against the Astros at the FITTEAM Ballpark of the Palm Beaches at 1:05 p.m. ET.