2004 Topps Baseball is a 732-card set divided into two 366-card series. Card 7 does not exist as it was retired by Topps in 1997 in honor of Mickey Mantle. As a result, the checklist ends at card 733. While there are several rookie cards in the set, the vast majority are of prospects who failed to live up to their early promise. These players include Zach Duke, Lastings Milledge and Conor Jackson. The most significant rookie today is Yadier Molina.