A native of the Dominican Republic, Alcántara was raised in San Juan de La Maguana.
Santo Domingo is the capital of the Dominican Republic, and his parents sent him there when he was just 11 years old so he could attend school and play baseball.
In order to focus on his baseball career, he dropped out of school in the eighth grade. Alcántara, a 17-year-old international free agent, signed with the St. Louis Cardinals in July 2013.
The Dominican Summer League Cardinals signed him in 2014, and he spent the entire season there, going 1–9 with a 3.97 ERA in 12 appearances (11 starts).
In 2015, he pitched for the Gulf Coast Cardinals, posting a 4–4 record and a 3.22 ERA in 12 games pitched. In 2016, he began his career with the Peoria Chiefs.
He struck out 14 in a row in a start for the Chiefs in May, tying the franchise record. July 2016 saw him join the Palm Beach Cardinals.
There were 23 starts for both teams in 2016, in which he went 5-11 with a 3.96 earned run average (ERA).
With the Springfield Cardinals, Alcántara has started the 2017 season. Cardinals elevated him to the majors on September 1, 2017 with a 7–5 record and 4.31 ERA in 125.1 innings.
AFL Surprise Saguaros selected him for their Fall Stars Game after he was reassigned by the Cardinals after the regular season ended. He threw a total of 15 innings in the AFL, with a 1–2 record and a 4.20 ERA in five starts.
Who Drafted Sandy Alcantara?
At the age of 17, Alcántara signed a contract as an international free agent with the St. Louis Cardinals in July 2013.