San Lorenzo swoop for Ortigoza
Argentine-born Ortigoza, who helped Paraguay reach the 2010 World Cup quarter-finals, moved from Argentinos Juniors, champions of last season's Clausura.
No figures were given but Clarin newspaper said Ortigoza cost $2.5 million with Argentinos retaining 20 percent of future transfer fees.
San Lorenzo, one of Argentina's traditional "Big Five" clubs, have strengthened their squad for the Clausura championship kicking off next weekend and they hope to qualify for the Copa Sudamericana, South America's equalivalent to the Europa League.
"Our obligation is to fight for everything we play for," club president Carlos Abdo said on Friday night when San Lorenzo unveiled their recruits including Uruguayan striker Juan Manuel Salgueiro, signed from Argentine champions Estudiantes.
"I'm very happy, the penny hasn't dropped yet. I've come to one of the big clubs and I hope to adapt quickly," the 26-year-old Ortigoza, regarded as the best holding midfielder in the Argentine league, told a news conference.
Argentine striker Claudio Bieler, a Libertadores cup winner with LDU Quito of Ecuador in 2009, has joined Newell's Old Boys on loan after an unsettled year with Racing Club.