The Nationals announced on Friday that they’ve optioned left-handers Shinnosuke Ogasawara and DJ Herz to Triple-A Rochester. Infielder Nasim Nunez and catcher Drew Millas were also sent down. As Mark Zuckerman of MASNsports.com writes, this essentially finalizes Mitchell Parker as the season-opening fifth starter.

Manager Dave Martinez said early in camp that MacKenzie Gore, Trevor Williams, Michael Soroka and Jake Irvin had rotation spots secure. The final job was up for grabs among Parker, Herz and Ogasawara. The former seemed to be the favorite going into camp, as he’d pitched to a 4.29 ERA in 29 starts as a rookie. Herz and Ogasawara probably had to pitch very well this spring to jump him on the depth chart.

That didn’t happen. Parker had the steadiest Spring Training performance. He allowed five runs with eight strikeouts and four walks across 12 1/3 innings. While that’s not exactly a dominant showing, Herz and Ogasawara both struggled. Herz gave up nine runs in 9 2/3 frames. He issued nine walks and only managed four strikeouts. Ogasawara was tagged for 19 runs (15 earned) over 12 innings. The Japanese southpaw recorded 10 strikeouts and walked eight.

Ogasawara signed a two-year, $3.5MM free agent deal over the winter. Unlike many NPB/KBO signees, he did not get a contractual clause that prohibits the team from sending him to the minors. He’ll begin his U.S. career in Triple-A after posting a 3.12 ERA with a modest 13.6% strikeout rate in his final NPB season. Herz made his big league debut last season. He struck out nearly 28% of opponents with a solid 4.16 ERA in 19 starts. He hasn’t consistently thrown strikes in the minors, though, and he clearly has not looked sharp this spring.