Cordero made his MLB debut on August 2, 1999, pitching the ninth inning against the Chicago White Sox at Tiger Stadium. The first batter he faced was Chris Singleton, who grounded out. After Frank Thomas hit a single, Cordero managed to strikeout both Magglio Ordóñez and Brian Simmons to end the inning. The White Sox ended up winning the game 6–2. Cordero earned his first MLB victory on August 31, 1999 in a 14–6 win over the Texas Rangers. He finished the season with a 2–2 record and a 3.32 ERA in 20 games out of the bullpen. On September 27, 1999, Cordero transported the home plate of the old Tiger Stadium after the last game played there to Comerica Park along with pitchers Matt Anderson and Jeff Weaver.