Although the additions of starting pitchers Ted Lilly and Miguel Batista and reliever Justin Speier were relatively successful, veteran Pat Hentgen faltered throughout the season and retired on July 24.
Rookies and minor league callups David Bush, Jason Frasor, Josh Towers and others filled the void in the rotation and the bullpen; however, inconsistent performances were evident.
The offense really sputtered due to the injuries of Wells, Delgado, Catalanotto and others, although in their absence, Josh Phelps emerged as the team's go to guy, hitting 12 homers and driving in 51 runs before being limited to playing against left-handed pitching and was traded to the Cleveland Indians.
With the team struggling in last place and mired in a five-game losing streak, manager Carlos Tosca was fired on August 8, 2004, and was replaced by first-base coach John Gibbons through the end of the season.
The Jays' trying year would also touch long-time radio announcer Tom Cheek, who had to break his streak of calling all 4,306 regular season games in franchise history, upon the death of his father.
However, the Jays' annus horribilis continued after the game, when it was announced that former pitcher and current TV broadcaster John Cerutti died suddenly of natural causes at the age of only 44.
A few days before Christmas, the Jays also mourned the loss of former first baseman Doug Ault, who had hit two home runs in the team's inaugural game in 1977; he was only 54 years old.
Just days after superstar Carlos Delgado became a free agent after the club refused arbitration, the Jays announced the signing of Manitoban third baseman Corey Koskie, formerly of the Minnesota Twins.