Plesac attended Crown Point High School, where he was not only a standout pitcher for the baseball team but also played football and basketball for the Bulldogs. He took his baseball talents to Ball State University in 2014 and earned Collegiate Baseball Newspaper Freshman Pitcher of the Year honors after posting a 12-2 record with a 2.11 ERA. 

In 2016, the Cleveland Guardians selected the right-hander in the 12th round of the MLB Draft. By 2019, Plesac had received the call to the Major Leagues, making his debut at Fenway Park against David Price and the defending World Series champion Boston Red Sox. Plesac pitched in the majors from 2019 through 2023 with Cleveland, and in 2024 he made three starts for the Los Angeles Angels. 

Last season, Plesac signed with the Atlantic League’s Long Island Ducks. In seven games, he posted a 2.84 ERA and struck out 33 batters before his contract was transferred to the St. Louis Cardinals, who assigned him to Triple-A Memphis. This year, the 31-year-old pitched in Mexico, where he made 13 appearances, posting a 6.79 ERA with 46 strikeouts in 62.1 innings.