Ureña was signed as an international free agent by the Blue Jays for $725,000 in 2012, and played his first professional season split between the Dominican Summer League Blue Jays and Gulf Coast League Blue Jays. In 64 games with the DSL Blue Jays, he batted.296 with one home run and 35 runs batted in. He then played seven games in the Gulf Coast League, batting.333 with three RBI. Ureña was promoted to the Rookie AdvancedBluefield Blue Jays of the Appalachian League for the start of the 2014 season, and recorded a 28-game streak of reaching base safely. In 53 games, he hit.318 with two home runs and 20 RBI before he was promoted to the Short Season-AVancouver Canadians on August 21. Ureña appeared in nine games for Vancouver, batting.242 with five RBI. On September 24, Ureña was named the Most Valuable Player for Bluefield in 2014. He began the 2015 season with the Class-ALansing Lugnuts. On June 5, Ureña was named a Midwest League midseason All-Star. At that time, he led the Lugnuts with seven home runs, and had 35 RBI. Ureña was called up to the Advanced-ADunedin Blue Jays in early July, and played 30 games there before returning to Lansing. In 121 games played, he batted.262 with 16 home runs and 66 RBI. In the offseason, he appeared in 33 games with the Gigantes del Cibao of the Dominican Winter League. Batting against pitchers that were over seven years of age older than him on average, Ureña hit.258 with five RBI. Ureña was invited to Major League spring training on January 12, 2016, and reassigned to minor league camp on March 12. He was assigned to the Dunedin Blue Jays to open the 2016 minor league season. Ureña recorded his first career five-hit game on July 9 which gave him 91 hits on the season, raising his batting average to.292 and tying him with Scott Kingery for first place in the Florida State League. On July 27, Ureña was ranked 91st on MLB's Top 100 Prospects list, and was named the Blue Jays top prospect. He was promoted to the Double-ANew Hampshire Fisher Cats on August 3, and had three hits in his debut that day. On August 10, Ureña hit three triples against the Bowie Baysox, which set a Fisher Cats single-game record. In 127 games in 2016, he hit.295 with eight home runs and 59 RBI. The Blue Jays added him to their 40-man roster after the season. Ureña spent the entire 2017 minor league season with Double-A New Hampshire, and hit.247 with five home runs and 60 RBI in a career-high 129 games played. Following his September callup to the Blue Jays in the previous season, Ureña was assigned to the Triple-ABuffalo Bisons to start the 2018 season. However, due to an intercostal strain which included a rehab assignment with the Dunedin Blue Jays, he did not join the Bisons until May 2.
