Atlanta Braves Avilán signed with the
Atlanta Braves as an international
free agent in 2005 In 2009, he was promoted to the
Danville Braves of the
Appalachian League, where he made 14 appearances, including three starts and had a 3.05 ERA with two saves. In 2011, with the
Mississippi Braves of the
Southern League, he was 4–8 with a 4.57 ERA in 36 appearances, including 13 starts. He began the 2012 season in Mississippi, where he was 3–6 with a 3.23 ERA 16 games (12 starts). He made his first appearance on July 14 against the
New York Mets, striking out the only batter he faced (
Ike Davis). In 31 appearances that season for the Braves, he had an ERA of 2.00. However, he struggled through the first half of the 2014 season, recording a 4.85 ERA in 47 games. Avilán was demoted to Triple A Gwinnett on July 19, 2014, and replaced by
Chasen Shreve. He would finish the 2014 season with a 4.57 ERA in 62 games. He pitched in 23 games for the Dodgers with a 5.17 ERA. At the conclusion of the season, the Dodgers signed him to a one-year, $1.39 million, contract to avoid
salary arbitration though he began the season with the Triple-A
Oklahoma City Dodgers after experiencing control problems in
spring training. He split the season between the minors and the majors, appearing in 33 games for Oklahoma City, with a 4.24 ERA and 27 games for Los Angeles, with a 3.20 ERA. He also pitched in innings in the playoffs between the
2016 National League Division Series and the
2016 National League Championship Series, without allowing any earned runs. Avilán spent the entire 2017 season in the Dodgers bullpen. In 61 games, he had a 2–3 record and 2.93 ERA.
Chicago White Sox On January 4, 2018, Avilán was traded to the
Chicago White Sox in a three-team trade that also sent Jake Peter and
Scott Alexander to the Dodgers,
Joakim Soria to the White Sox, and
Trevor Oaks and
Erick Mejia to the
Kansas City Royals.
Philadelphia Phillies On August 22, 2018, Avilán was traded to the
Philadelphia Phillies in exchange for minor league pitcher Felix Paulino. Between the two teams, in 2018 he was 2–1 with two saves and a 3.77 ERA. He threw a change-up 48.1% of the time, tops in MLB. He elected free agency on November 30. In his career through 2018 he had held left-handed batters to a batting average of .213, and right-handed batters to a batting average of .244.
New York Mets On January 10, 2019, Avilán signed a minor league deal with the
New York Mets that included an invitation to
spring training. He made the team and had his contract purchased for opening day. On April 15, 2019, Avilán earned his first victory as a Met in a game against the
Philadelphia Phillies. On the season, he registered an 5.06 ERA with 30 strikeouts in 32.0 innings of work. He elected free agency on October 31, 2019.
New York Yankees On February 3, 2020, Avilán signed a minor league contract with the
New York Yankees. On July 21, Avilán had his contract selected to the 40-man roster. On August 28, Avilán was released by the Yankees two days after being placed on the injured list due to shoulder inflammation. He had pitched to a 4.32 ERA across innings in 2020.
Washington Nationals On December 14, 2020, Avilán signed a minor league contract with the
Washington Nationals organization. On March 28, 2021, Avilán was selected to the 40-man roster. On April 17, it was announced that Avilán had suffered a tear in his left
UCL, requiring
Tommy John surgery and ending his season early. He was placed on the 60-day injured list on April 30. In 4 games for the Nationals in 2021, Avilán registered a 12.60 ERA with 4 strikeouts. Avilán became a free agent following the season and re-signed with the Nationals on a minor league contract on November 29, 2021. In 2022, Avilán spent the season in the Nationals' minor league system. Playing in 36 games split between the High–A
Wilmington Blue Rocks and Triple–A
Rochester Red Wings, he recorded a cumulative 4.84 ERA with 39 strikeouts in innings pitched. Avilán elected free agency following the season on November 10, 2022. On October 20, 2023, Avilán retired from professional baseball. ==Coaching career==