Former Valencia midfielder Pablo Aimar on Wednesday announced his retirement at the age of 35. The Argentine playmaker made the decision after River Plate Coach Marcelo Gallardo left him out of the squad for the Copa Libertadores semifinal series against Guarani of Paraguay. Due to injury problems, Aimar had made just two first team appearances since joining River in May. The former Argentina international won the 2001-02 and 2003-04 La Liga titles as well as the 2004 UEFA Cup with Valencia under Rafael Benitez. He also had spells at Real Zaragoza and Portuguese giant Benfica, where he won the Portuguese Primeira Liga in 2009-10.