|Full name||Carlos Guillermo Fren|
|Date of birth||December 27, 1954|
|Place of birth||, Argentina|
|2005||Instituto de Córdoba|
|2007||12 de Octubre|
|* Senior club appearances and goals counted for the domestic league only and correct as of 2009|
Fren began his playing career in 1973 with Argentinos Juniors. Between 1976 and 1978 he played alongside teenage sensation Diego Maradona in the Argentinos midfield. He made over 200 appearances for the Paternal club before joining Independiente in 1978.
Fren began coaching in the youth teams of Nueva Chicago and Vélez Sársfield. His first first team appointment was his former club Independiente in 1991. In 1994, he teamed up with Diego Maradona as joint manager of Deportivo Mandiyú. In 1995, the pair had another unsuccessful attempt at management with Racing Club.
In 1996, Fren notoriously spent a single game in charge of Argentinos Juniors before resigning.
From there, Fren went on to coach the reserve team of Talleres de Córdoba and then work as assistant coach to José Pastoriza at Independiente. In between 2004 and 2005, he worked with Luis Garisto at Instituto de Córdoba and in 2007, he had a spell in charge of 12 de Octubre of Paraguay.