Bautista began the 2017 season with the Class AAA Syracuse Chiefs in the International League. The Washington Nationals promoted him to the major leagues on April 29, 2017. He made his major league debut on April 30 in a 23-5 Nationals victory over the New York Mets at Nationals Park in Washington, D.C., batting twice and going 0-for-2 against Mets catcher Kevin Plawecki, who was making his first-ever major league appearance as a pitcher. On May 6, in a 6–2 Nationals victory over the Philadelphia Phillies at Citizens Bank Park in Philadelphia, he made his first career major-league start, playing right field, and got his first career major-league hit, a single through the infield off Phillies pitcher Vince Velasquez. The Nationals optioned Bautista back to Syracuse on May 8. The Nationals recalled Bautista on August 27, but optioned him back to Syracuse the next day. They called him back up again on September 7, and he finished the regular season with the Nationals. He completed the season having played in 17 major-league games, batting.160 with four hits – all singles – in 25 at-bats, scoring two runs, and with a slugging percentage of.160 and an on-base percentage of.222. In the minor leagues, Bautista played 43 games for Syracuse and 13 for the Gulf Coast League Nationals during 2017. He hit a combined.259 for the two teams, with 14 RBIs and nine stolen bases.
2018
Bautista participated in 2018 major-league spring training before the Nationals optioned him to the Class AAA Syracuse Chiefs on March 14. He was reassigned to the Class AA Harrisburg Senators on April 2 and began the season with them, but was promoted back to Syracuse on April 12. He had made 45 plate appearances for Syracuse, batting.429 with a.966 on-base-plus-slugging percentage when, on April 24, the Nationals called him up to the major leagues. He appeared in nine games, usually as a late-game replacement or a pinch-runner, made one start, and went 0-for-6, striking out once and scoring a run before the Nationals optioned him back to Syracuse on May 7 to make room on their 25-man roster when they activated right-handed relief pitcher Shawn Kelley from the 10-day disabled list. Bautista made another 46 plate appearances for Syracuse, batting.300 with a.749 OPS, before colliding with another player during a game against the Rochester Red Wings at Rochester, New York, on May 17, tearing the anterior cruciate ligament, lateral collateral ligament, and meniscus in his left knee. The injury required season-ending surgery. He ended his season with an overall.303 batting average in the minor leagues, with three doubles, a triple, a home run, seven RBIs, and six stolen bases in the minors for the year. On June 9, the Nationals released Bautista to make room for Adam Eaton on their roster when they activated Eaton from the 60-day disabled list. On June 13, Washington re-signed Bautista to a minor league deal.
