Aaron Barrett worked on his fielding earlier in spring training, but it’s his pitching that earned him a spot on the opening day roster. (John McDonnell/The Washington Post)

The Nationals named rookie right-hander Aaron Barrett to their opening day bullpen and winnowed the competition for their final roster spot with a flurry of cuts Tuesday afternoon, some of which left the door open for the Nationals to acquire a player from outside the organization.

The Nationals optioned first baseman Tyler Moore to Class AAA Syracuse and released infielder Jamey Carroll, which left catcher Sandy Leon and speedy utility man Jeff Kobernus as the lone remaining contenders for the Nationals’ final bench spot currently in camp. They also released right-handed starter Chris Young and optioned relievers Xavier Cedeno and Ryan Mattheus to Syracuse.

“None of them were easy, certainly,” Manager Matt Williams said. “But they were moves that we had to make. We wanted to let them know today so they can make plans for anything they need to make plans for.”

The Nationals may still be seeking another player to add to their bench mix. The Nationals contacted infielder Kevin Frandsen after Frandsen opted out of his contract with the Philadelphia Phillies, according to a person with knowledge of the situation.

Frandsen, 31, opted out of his contract Tuesday, a day after the Phillies sent him to Class AAA. If Frandsen had stayed in the Phillies’ organization, he would have earned $900,000 guaranteed. It’s not clear when Frandsen may come to a decision on his next team. The Nationals were one of two or three teams who reached out to him.

Frandsen, a right-handed hitter, batted .280/.333/.389 with seven home runs over the past two seasons with the Phillies. He played first base, second base and third base. The Nationals value his ability to play both corner infield spots and his potential as a pinch hitter. In 88 plate appearances against left-handed pitchers last year, Frandsen hit .311/.409/.459. He also led the majors with 14 pinch hits.

The Nationals opened the door for Barrett to make their bullpen when they optioned Cedeno, a lefty, and Mattheus, a right-hander who battled a chest injury early in spring, to Syracuse. Barrett, Class AA Harrisburg’s closer last year, did not allow an earned run all spring on the strength of his vicious slider and low-to-mid 90s fastball.

“When it came down to it, Aaron has showed he’s able to compete at this level,” Williams said. “He’ll be a valuable piece to our bullpen and get in a lot of games for us.”

With Barrett in the bullpen, the loser of the Nationals’ fifth starter competition between Tanner Roark and Taylor Jordan will be sent to the minors. Williams wants to ensure Doug Fister, who has recovered from elbow inflammation, pitches Thursday without a setback before making that decision.

The Nationals value Kobernus because of his speed and his ability to play almost everywhere on the diamond. They are considering the possible addition of Leon because a third catcher would allow them to use either Jose Lobaton or Wilson Ramos as a pinch hitter without the risk of running out of catchers due to one injury.

“I want to get Wilson as many at-bats as I can,” Williams said. “He’s one of our best RBI guys. There’s going to be days when he’s not playing where I want to use his bat off the bench.”

The Nationals sent Moore, a power hitter on their bench much of the last two seasons, to the minors because Williams did not envision enough at-bats for him in the majors. The Nationals want him sharp in the likely event he ascends to the majors.

“Tyler’s history is that when he has consistent at-bats, he does well,” Williams said. “He’s got power. For him, right now, it’s about at-bats. If we make that decision at some point during the season, he’ll have been playing and have timing. He needs to be ready if we need him.”

Williams raved about Carroll, a member of the original 2005 Nationals, multiple times this spring. Coaches loved his perfect fundamentals and professionalism. But with Danny Espinosa securing an infield bench spot with his strong spring, the Nationals feared he would not receive enough playing time.

If Carroll, 40, cannot find a major league job elsewhere, he would not play in the minors. By releasing him, the Nationals cut ties.

“That was the toughest one that I’ve had so far,” Williams said. “But I just didn’t happening for us. I don’t want to make it go down to the last wire. There are other teams out there looking for a middle infielder. Certainly, we’ll allow him to do that and help him do that if we can. I think there’s more in the tank for him. I think he’ll land somewhere and get a big league job. He’s a pro in every aspect.”