MLB Showdown League
The 2004 MLB Showdown League promo set consisted of 71 cards. (As an eBay Partner, I may be compensated if you make a purchase) (eBay Link)
P01- Barry Larkin
P02- Barry Zito
P03- C.C. Sabathia
P04- Carlos Delgado
P05- Derek Lowe
P06- Fernando Tatis
P07- Frank Thomas
P08- Greg Maddux
P09- Hideki Matsui
P10- Jason Isringhausen
P11- Jeff Kent
P12- Jimmy Rollins
P13- Mike Piazza
P14- Josh Beckett
P15- Juan Pierre
P16- Ken Griffey Jr.
P17- Luis Castillo
P18- Mike Remlinger
P19- Moises Alou
P20- Paul Lo Duca
P21- Preston Wilson
P22- Rafael Furcal
P23- Reggie Sanders
P24- Shigetoshi Hasegawa
P25- Tony Batista
P26- Brady Clark
P27- Carlos Febles
P28- Damien Jackson
P29- Darren Bragg
P30- David Segui
P31- Jesse Foppert
P32- Greg Norton
P33- Hee Seop Choi
P34- Henry Mateo
P35- Jake Peavy
P36- Jeff Reboulet
P37- Kevin Witt
P38- Livan Hernandez
P39- Mike Kinkade
P40- Paul Shuey
P41- Ricky Ledee
P42- Ricky Stone
P43- Roger Cedeno
P44- Ron Calloway
P45- Ryan Wagner
P46- Shawn Estes
P47- Todd Pratt
P48- Tom Wilson
P49- Tony Graffanino
P50- Troy O'leary
P51- Andruw Jones
P52- Manny Ramirez
P53- Ken Griffey Jr.
P54- C.C. Sabathia
P55- Josh Beckett
P56- Brad Lidge
P57- Jeff Bagwell
P58- Jeff Kent
P59- Francisco Cordero
P60- Hank Blalock
P61- Mark Teixeira
P62- Michael Young
P63- Carlos Delgado
P64- Miguel Tejada
P65- Greg Maddux
P66- Ivan Rodriguez
P67- Andy Petitte
P68- Craig Biggio
P69- Roger Clemens
P70- Javier Vazquez
P71- Alex Rodriguez (Beckett magazine exclusive)
September 2004 Beckett Magazine that contained the ARod card