He pitched for the Milwaukee Brewers, Toronto Blue Jays, Chicago Cubs, Pittsburgh Pirates, Arizona Diamondbacks, and Philadelphia Phillies.

A hard thrower with a mid-90 mph fastball and great slider, Plesac was originally a starting pitcher before becoming the closer of the Milwaukee Brewers.

Plesac served primarily as a left-handed specialist from the mid-1990s until the end of his career, pitching for the Blue Jays twice, the Diamondbacks, and the Phillies.

[2] He was elected to the American League All-Star team three times (1987, 1988 and 1989) and ended his career with a 65–71 record, a 3.64 ERA in 1,064 games and 1,072 innings pitched.

He struck out the only batter he faced, Ryan Langerhans, to record the third out in the top of the ninth inning on September 28, 2003, as the Phillies lost to the Atlanta Braves, 5–2.