Nobody, it was Jackie Robinson, whose number was retired throughout Baseball in 1997. The only player who still wears #42 is Mariano Rivera, The New York Yankees closer, who had the number before it was retired.
The San Diego Padres is a baseball team.
There are 5 retired numbers 6,19,31,35 and 42
Will Venable is number 25 on the San Diego Padres.
Alex Torres is number 54 on the San Diego Padres.
Alexi Amarista is number 5 on the San Diego Padres.
Andrew Cashner is number 34 on the San Diego Padres.
Blaine Boyer is number 58 on the San Diego Padres.
Bobby LaFromboise is number 57 on the San Diego Padres.
Cameron Maybin is number 24 on the San Diego Padres.
Carlos Quentin is number 18 on the San Diego Padres.
Casey Kelly is number 49 on the San Diego Padres.
Chase Headley is number 7 on the San Diego Padres.