He played for the Boston Red Sox, Arizona Diamondbacks, Kansas City Royals, Pittsburgh Pirates, St. Louis Cardinals, Milwaukee Brewers, and San Diego Padres.

Suppan pitched at Crespi Carmelite High School in California's San Fernando Valley.

He pitched one no-hitter as a freshman and another as a senior against Harvard-Westlake School in the midst of a 42-inning scoreless streak.

[2][3] He was selected by the Boston Red Sox with the 49th pick of the 1993 Major League Baseball draft[2] and signed for $190,000.

Suppan was dealt at the trading deadline back to the Red Sox for their playoff stretch run, along with Anastacio Martinez and Brandon Lyon for prospects Freddy Sanchez and Mike Gonzalez.

The Cardinals signed Suppan as a free agent in 2004, and he embarked upon a career year, posting a 16–9 record and a 4.16 earned run average, with 110 strikeouts, 65 walks, and 192 hits allowed in 188 innings.

Suppan has hit two career Major League home runs, both off Steve Trachsel of the New York Mets.

He did not factor in the decision, giving up only one run in seven innings, but the Cardinals won 3–1, earning him the National League Championship Series MVP.

Milwaukee fans began a practice of wearing paper bags over their heads and throwing soup cans on to the field during Suppan's starts.

Suppan, along with teammates J. J. Hardy, Bill Hall, and Chris Capuano appeared in an episode of The Young and the Restless which aired on CBS on June 20, 2007.

He was a finesse pitcher, using a variety of pitches with good movement to create weak contact for hitters.

[33] Soup's Grill closed in January 2016 to devote his time to being pitching coach for the Idaho Falls Chukars.

[34] Suppan is a devout Roman Catholic, appearing in the DVD Champions Of Faith and in Rosary Stars Praying the Gospel.

[35] He appeared in a political advertisement alongside Patricia Heaton, Jim Caviezel, Mike Sweeney, and Kurt Warner, among others, during the 2006 World Series.

The timing of both ads during a World Series that featured the St. Louis Cardinals was intended to draw the particular attention of Missouri voters.