The Washington Nationals made the following roster moves on Tuesday. Nationals President of Baseball Operations and General Manager Mike Rizzo made the announcements.

• Selected the contracts of right-handed pitcher Zach Brzykcy, right-handed pitcher Cole Henry, left-handed pitcher DJ Herz and left-handed pitcher Mitchell Parker.
• Designated right-handed pitcher Cory Abbott and first baseman Dominic Smith for assignment.
• Requested Unconditional Release Waivers for right-handed pitcher Andrés Machado to pursue an opportunity in Japan.

Brzykcy (BRICK-see), 24, took part in his first Major League Spring Training in 2023 after a breakout campaign the previous year in which he went 8-2 with 14 saves and a 1.76 ERA in 51 games across three levels of Washington’s system. The hard-throwing reliever ranked second in the organization with 14 saves and ranked among all Minor League pitchers (min. 60.0 IP) in opponents’ batting average (3^rd, .157), ERA (5^th, 1.76) and strikeouts per 9.0 innings (14^th, 13.94). Brzykcy was the only pitcher in all of Minor League Baseball with at least 14 saves and at least eight wins in 2022.

Signed as a non-drafted free agent out of Virginia Tech following the 2020 First-Year Player Draft, Brzykcy missed the 2023 season after undergoing Tommy John surgery in April.

Henry, 24, has pitched to a 3.29 ERA, a .189 opponents’ batting average, 1.02 walks/hits per inning pitched and 11.30 strikeouts per 9.0 innings in 34 games across three professional seasons. He has recorded 141 strikeouts with 39 walks in 112.0 innings pitched since making his debut in 2021. Henry was selected in the second round of the 2020 First-Year Player Draft out of Louisiana State University.

Herz, 22, went 3-3 with a 3.43 ERA in 22 starts between Double-A Tennessee and Double-A Harrisburg in 2023. He ranked third in all of Double-A and 13^th in all of Minor League Baseball (min. 90.0 IP) with a .196 opponents’ batting average. His 133 strikeouts in 94.1 innings pitched ranked second among all Double-A left-handed pitchers. He was acquired by the Nationals along with shortstop Kevin Made from the Chicago Cubs in exchange for Jeimer Candelario on July 31, 2023.

Herz is coming off an Arizona Fall League season in which he went 1-0 with a 3.71 ERA in five starts en route to being named an Arizona Fall League Fall Star. He ranked tied for third in the league with 25 strikeouts.

In 2022, Herz tied for the lead in Chicago’s Minor League system with 141 strikeouts in 95.1 innings pitched between High-A South Bend and Double-A Tennessee. He was named Chicago’s Minor League Pitcher of the Year in 2021 after leading the system with 131 strikeouts.

Davidjohn “DJ” Patrick Herz was originally selected by the Chicago Cubs in the eighth round of the 2019 First-Year Player Draft out of Terry Sanford High School in Fayetteville, North Carolina. He is 10-14 with a 3.64 ERA, a .178 opponents’ batting average and 13.20 strikeouts per 9.0 innings in 74 professional starts.

Parker, 24, led Washington’s Minor League system with 150 strikeouts, tied for the lead with nine wins, and ranked third in the organization with a .244 opponents’ batting average in 2023. He went 9-7 with a 4.72 ERA in a career-high 28 games (26 starts) between Double-A Harrisburg and Triple-A Rochester.

Parker went 4-2 with a 2.98 ERA (18 ER/54.1 IP), 66 strikeouts and just 15 walks from July 16 to September 2, his best stretch of the 2023 season. He tossed 7.0 innings and allowed just one hit twice this season, including July 16 vs. Richmond (SFG) when he tossed 7.0 innings of one-hit, shutout ball with eight strikeouts and two walks. On Aug. 25 at Reading (PHI), he struck out nine batters with one walk and three hits allowed in a career-high 8.0 innings.

A fifth-round pick in the 2020 First-Year Player Draft out of San Jacinto (TX) College, Parker is 19-23 with a 4.20 ERA and 11.35 strikeouts per 9.0 innings in 75 professional games (71 starts).