Stephen James Kolek (born April 18, 1997) is an American professional baseball pitcher for the Kansas City Royals of Major League Baseball (MLB). He has previously played in MLB for the San Diego Padres.
Kolek attended Shepherd High School in Shepherd, Texas. He enrolled at Texas A&M University, where he played college baseball for the Texas A&M Aggies from 2016 to 2018.
The Los Angeles Dodgers selected Kolek in the 11th round, with the 344th overall selection, of the 2018 Major League Baseball draft. He spent his first professional season with the rookieâÂÂlevel Ogden Raptors and SingleâÂÂA Great Lakes Loons, accumulating a 1.42 ERA with 30 strikeouts across 17 contests. Kolek returned to Great Lakes in 2019, going 7âÂÂ8 with a 5.00 ERA and 109 strikeouts in 27 games (25 starts). He did not play in a game in 2020 due to the cancellation of the minor league season because of the COVID-19 pandemic.
On April 28, 2021, the Dodgers traded Kolek to the Seattle Mariners in exchange for cash considerations. He split the year between the SingleâÂÂA Modesto Nuts, HighâÂÂA Everett AquaSox, and DoubleâÂÂA Arkansas Travelers. In 24 combined appearances, Kolek struggled to a 6.03 ERA with 67 strikeouts across innings pitched. In 2022, he made 27 starts for Arkansas, registering a 6âÂÂ13 record and 4.51 ERA with 138 strikeouts across innings of work. In 2023, Kolek made five scoreless appearances for Arkansas before being promoted to the TripleâÂÂA Tacoma Rainiers, where he spent the remainder of the year. In 44 appearances for Tacoma, he recorded a 4.23 ERA with 65 strikeouts and 4 saves across innings pitched.
On December 6, 2023, the San Diego Padres selected Kolek from the Mariners in the Rule 5 draft. On March 19, 2024, the Padres announced that Kolek made their Opening Day roster. In 42 appearances out of the bullpen, he compiled a 5.21 ERA with 39 strikeouts over innings pitched. Kolek was placed on the injured list with right forearm tendinitis on July 31. He was transferred to the 60âÂÂday injured list on September 1, officially ending his season. Kolek was optioned to the Triple-A El Paso Chihuahuas to begin the 2025 season.
In early May, Kolek was recalled to the major league team, this time to serve as a starter. He tossed scoreless innings in his May 4 season debut, allowing four hits and striking out four as he earned the win. His second career start, on May 10, was a complete-game shutout. Kolek tied a Modern Era-record for the largest margin in an individual shutout, as San Diego scored 21 against the Rockies. In 14 starts for San Diego, he compiled a 4-5 record and 4.18 ERA with 56 strikeouts across innings pitched.
On July 31, 2025, Kolek and Ryan Bergert were traded to the Kansas City Royals in exchange for catcher Freddy FermÃÂn.
His brother is Tyler Kolek, a former professional baseball player and 2nd overall pick by the Miami Marlins in 2014.