In 2008 with the GCL Mets, he batted.305/.350/.364. In 2010 with Savannah, he batted.292/.375/.359 and stole 45 bases. Puello was ranked the #77 prospect in the pre-2011 Baseball America rankings. Puello was added to the Mets' 40 man roster on November 18, 2011. After the 2012 regular season, he played for the Surprise Saguaros of the Arizona Fall League. In 2013 with Binghamton, he batted.326/.403/.547 and stole 24 bases in 331 at bats. Puello was suspended for 50 games on August 5, 2013, for his relationship to the Biogenesis clinic. The Mets outrighted Puello off of the 40-man roster in April. Puello was released by the Mets on August 19, 2015, after missing all but one game of the 2015 season with back pain.
During the 2016 offseason, Puello signed a minor league contract with the Texas Rangers. He played for the Round Rock Express of the Class AAAPacific Coast League. Puello had a June 1 opt-out clause if not on the major league roster. The Rangers granted Puello his release when they did not promote him to the major leagues. He signed a minor league contract with the Los Angeles Angels, and played for the Salt Lake Bees of the PCL.
Los Angeles Angels
The Angels promoted Puello to the major leagues on August 9, and he collected his first major league hit and two stolen bases that day. With AAA Salt Lake he batted.397/.440/.620 with 13 steals in 184 at bats.
Tampa Bay Rays
On August 19, 2017, the Tampa Bay Rays claimed Puello off waivers. He was outrighted to AAA on November 6, 2017. He elected free agency on November 6, 2017.
On December 14, 2017, Puello signed a minor league contract with the Arizona Diamondbacks. With AAA Reno in 73 games he batted.317/.426/.454 with 6 home runs and 33 RBI's in 249 at bats. He was released on August 1, 2018.
On August 3, 2018, Puello signed a minor league deal with the San Francisco Giants; with AAA Sacramento, he batted.289/.365/.311 with 4 RBIs in 45 at bats in 13 games. He became a free agent after the season.
Los Angeles Angels (second stint)
On November 26, 2018, Puello signed a minor league contract with the Los Angeles Angels. He did not make the team and was assigned to AAA Salt Lake Bees. He had his contract selected to the major leagues on May 28, 2019. He hit his first major league home run against the Oakland Athletics on May 29, 2019. He was designated for assignment on June 17, 2019 following the return of Justin Upton from injury.
Miami Marlins
The Angels traded Puello to the Miami Marlins on June 19, 2019. Puello was outrighted off the Marlins roster on October 23, and elected free agency on October 24.
On February 11, 2020, Puello was signed to a minor league deal by the Boston Red Sox. He was also announced as a non-roster invitee to Red Sox spring training.