by the Chilean Colo Colo, in a match so marred by Gimnasia's violence that Argentine Football Association's president Julio Grondona wrote a letter of apology to the president of the ANFP (the Chilean football federation). The pending second half against Boca Juniors was played on 8 November 2006. Boca Juniors scored four goals and won the match. After the match, Troglio and some of the players hinted that the team had received death threats from a fraction of their own supporters, who wanted to benefit Boca in its championship bid against Gimnasia's archrivals Estudiantes. Nevertheless, Estudiantes obtained the title in the end. La Plata District Attorney Marcelo Romero opened a criminal case and cited some club players and officers to testify. Player Marcelo Goux refused to play the next match and quit the team; he was soon followed by fellow players Martín Cardetti and Ariel Franco. Many articles condemned Muñoz's handling of the situation, accusing him of lying to the press, and of treating violent fans as his protégés. After a string of losses in the local championship and the Copa Libertadores, there were renewed calls for Muñoz to resign. Coach Troglio felt the burden of responsibility and quit his post on April 2, 2007. Gimnasia hired first famed Colombian trainer Francisco Maturana, and then Julio César Falcioni, both with limited success. 2007–08: New management In the December 2007 election, Muñoz did not run, and the candidate he supported lost to the opposition. New club president Walter Gisande hired former player Guillermo Sanguinetti as team coach and tried to convince former players, notably Diego Alonso and Guillermo Barros Schelotto, to return to Gimnasia. Only Alonso, who was playing in China, made the leap. Sanguinetti quit after a string of bad results that left Gimnasia in serious danger of relegation. Under new coach Leonardo Madelón, team results improved markedly, and as of the beginning of the 2009 Clausura tournament, Gimnasia is better positioned to stay in the Primera level. The new management also campaigned for a return to its traditional ground at El Bosque. Starting April 2008, the stadium underwent a structural engineering evaluation after all security measures requested by authorities were put in place. In June 2008, Gimnasia was allowed to play again at El Bosque''; the return took place in a match against Lanús, the last game of the Clausura 2008 championship. Mayor Pablo Bruera has indicated that the