Ávalos made his professional debut in 2001 for Cerro Porteño in Paraguay where he was part of two championship winning campaigns in 2001 and 2004. He also was the Paraguayan 1st Division topscorer in 2003.
In 2005 Ávalos spent some time on loan in Santos in Brazil before returning to Cerro.
In 2006 Ávalos joined Club Toluca in Mexico and joined Racing Club in 2007.
Avalos returned to Cerro once again in 2008 and in January 2010 he joined Argentine club Chacarita Juniors.
He returned to Paraguay within six months and then re-joined Cerro Porteño.
Prior to begin 2011 season he moved to Sol de América.