Aaron Barrett. (Nick Wass/Associated Press)

Over the past three games, the Nationals bullpen has logged 14 2/3 innings. And even though rookie right-handed reliever Aaron Barrett was impressive in the season’s first two weeks, the Nationals optioned him to Class AAA Syracuse and called up right-handed starter/reliever Blake Treinen. Barrett, 26, pitched in Friday’s 10-inning loss and Treinen, 25, was scheduled to pitch on Saturday, so he provided a fresh arm that could pitch multiple innings.

“The issue with Aaron is he has done everything we’ve asked him to do, and above and beyond,” Manager Matt Williams. “But the way our bullpen is situated right now, we needed a guy that could give us length. It’s one of those decisions that you make because you have to make it. Not because you want to make it. So Aaron was understanding. This is the way the game is sometimes.”

Barrett was a long-shot bullpen candidate to start spring training, but made the opening day roster with an impressive spring. In six major league games, he allowed only one hit, walked two and struck out six. His mid-90s fastball coupled with his wipe-out slider, and composure earned the coaching staff’s trust. Williams thrust Barrett into crucial spots despite his lack of major league experience and he thrived. But, the Nationals needed a rested arm in the taxed bullpen.

“If you look at it logistically, the bullpen has been pretty overworked at the moment,” Barrett said in the clubhouse before he left. “They just told me right now they need innings. It is what it is. Yeah, it stinks getting sent down, but at the same time, I’m not going to beat myself up about it. It’s not because it’s performance-based. We need innings. They told me hopefully around 10 days, ‘We’ll get you back up here and get the bullpen back to where it needs to be.’ They felt bad putting me in this situation, sending me down, because he told me I deserve to be here and I’ve done well at this point so far but I mean the team needs innings. That’s just part of it.”

Williams said Craig Stammen, who threw 52 pitches on Wednesday when Jordan Zimmermann was knocked out early, and Rafael Soriano, who had thrown back-to-back games on Wednesday and Thursday, were both available on Saturday. Ross Detwiler threw two innings on Friday and could pitch again but he has yet to throw back-to-back days as a reliever, so Williams wants to avoid him.

Based on the rules, Barrett would have to spend at least 10 days in the minor leagues, unless there is an injury, before he can be recalled. Williams said there is a “very strong chance” Barrett will be back after 10 days. “The way he’s pitched, he’s definitely deserving,” Williams said.

In his place, the Nationals called up another impressive arm in Treinen. The right-hander pitched in relief during spring training and wowed team officials with his high 90s stuff, slurve and maturity. Treinen was one of three players acquired from Oakland before the 2013 season in the Michael Morse trade. Treinen returned to starting at Syracuse and made one start already, allowing two unearned runs over five innings on Monday.

Treinen was given the news by Syracuse Manager Billy Gardner Jr. between 11:30 p.m. and midnight Friday. He then called his agent, family and fiancee with the news. He finally fell asleep around 1:3o a.m. and was up at 4 a.m. to catch a flight. Syracuse was in Scranton, Penn. for a road series.

“Internally, I was screaming,” Treinen said. “Externally, I was pretty relaxed. I think it took me until I went to bed when I realized because then it’s hard to sleep but I feel like I’m ready. I’m excited. Performance-wise, I feel like I’m here for a reason.”

Treinen said his parents and brother flew in from Kansas in to Atlanta in time for the game. He has played pranks on his parents about being traded and such, but this time he woke them up at midnight with the news of a lifetime. His strong spring performance gives him confidence that he can get major league hitters out. But he didn’t expect to be in the big leagues in April. In order to make room for him on the 40-man roster, the Nationals recalled infielder/outfielder Jeff Kobernus and then placed him on the 60-day disabled list after he had surgery this week on a broken bone in his left hand.

“I don’t think I was expecting to get a call this early by any means especially the way that they’ve been lights out,” Treinen said. “I just feel like it caught me off guard a little bit. But I’m excited. How can you not be?”