Loáisiga was promoted from the Class A-Advanced Florida State League to the Class AA Eastern League after posting a 3–0 record and 1.35 earned run average in four starts for the Tampa Yankees.
In six starts in Trenton, he had a 4.32 ERA, but 32 strikeouts in 25 innings of work impressed. Loáisiga was called up to the majors when Yankees starter Masahiro Tanaka was sidelined by an injury.
On June 15, 2018, he made his MLB debut, pitching five scoreless innings and earning the win. He was the first player from Nicaragua to play for the New York Yankees, a distinction he still has today.
On July 2, he was optioned to the Scranton/Wilkes-Barre RailRiders of the Class AAA International League after making four appearances with the Yankees, with a 3.00 ERA in the process.
After the expansion of the roster, he was called up to the Yankees on September 2. He pitched for the Yankees in 2018 and threw a total of 24+23 innings. In 2019, he appeared in 15 games for the Yankees and pitched 31+2/3 innings.
Loáisiga signed with the Yankees for the 2020 season and will serve as a swing man, making appearances both in the starting lineup and in the bullpen.
Loáisiga’s first career save came against the Cleveland Indians on April 24, 2021.
Loáisiga made history two months later on June 25 when he struck out the Boston Red Sox’s Michael Chavis, Alex Verdugo, J. D. Martinez, and Xander Bogaerts in the seventh inning for the Yankees’ first-ever four-strikeout inning.
The Yankees placed Loáisiga on the COVID-19 disabled list and the MLB postponed their game against the Boston Red Sox to the start of the second half of the season in July 2021 after he tested positive for the virus along with teammates Nestor Cortes and Wandy Peralta.
There were 69 strikeouts in 70+2/3 innings for Loáisiga in the 2021 season.
How Did The Yankees Get Jonathan Loaisiga?
In February 2016, he signed with the New York Yankees. He started the season with the Charleston RiverDogs, but after only one game, he was forced to undergo Tommy John surgery due to an injury. After the season, the Yankees added him to their 40-man roster.