Here is a list of San Francisco Giants players and personnel who have worn No. 21 since 1958:
Sergio Romo wore No. 54 for the San Francisco Giants.
Jake Dunning wore No. 51 with the San Francisco Giants.
Pitcher Manny Aybar wore No. 64 during the 2002 season.
Adam Duvall wore No. 37 when he played with the San Francisco Giants during the 2014 season.
Jeremy Affeldt wore No. 41 during his career with the San Francisco Giants (2009-2015)..
Santiago Casilla wore No. 46 for the San Francisco Giants.
Sergio Romo wore No. 54 for the San Francisco Giants.
Jake Dunning wore No. 51 with the San Francisco Giants.
Juan Gutierrez wore No. 57 for the 2014 San Francisco Giants.
Juan Perez wore No. 2 for the San Francisco Giants from 2013 to 2015.
Ryan Vogelsong wore No. 32 with the San Francisco Giants. In previous years with the team, he wore the numbers 51 and 14.
Joaquin Arias wore No. 13 for the San Francisco Giants from 2012 to 2015.
Brandon Hicks wore No. 14 as a member of the 2014 San Francisco Giants.
Pitcher Manny Aybar wore No. 64 during the 2002 season.
Adam Duvall wore No. 37 when he played with the San Francisco Giants during the 2014 season.
Hector Sanchez wore No. 29 when he played for the San Francisco Giants from 2011 to 2015.
Marco Scutaro wore No. 19 for the San Francisco Giants from 2012 to 2014..