Kammala jumla mai zuwa: Gamarra ya bayyana ga tawagar kasar Paraguay sau 110, inda ya zira kwallaye 12, daga 1993 zuwa 2006, yana wakiltar tawagar a manyan gasa 10 kuma ya jagoranci tawagar a lokacin karshen aikinsa. Shi ne na biyu mafi yawan 'yan wasan da aka buga a tawagar kasa, wanda Paulo da Silva ya karya a shekarar 2013. Gamarra ya fito ne a Paraguay a gasar cin kofin duniya na FIFA uku (1998, 2002 da 2006), gasar cin kofin Copa América biyar (1993, 1995, 1997, 1999 da
2004), da kuma sau biyu a Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin Wasannin An zabi Gamarra a matsayin dan wasan kwallon kafa na Paraguay na shekara a shekarar 1997 da 1998, kuma an kuma hada shi a cikin 1998 FIFA World Cup Team of the Tournament.