In 2007, he lived his worst season in the team, but in the next season, under the coach Nelson Acosta, the club reached his fourth title in the Chilean Primera División, after 32 years without a league title.
Nelson Bonifacio Acosta López, nicknamed Pelado Acosta (Bald Acosta), (born 12 June 1944 in Paso de los Toros, Uruguay) is a former Uruguayan footballer.
Nelson Mandela | Willie Nelson | Nelson | Horatio Nelson, 1st Viscount Nelson | Nelson, New Zealand | Ricky Nelson | Nelson Rockefeller | Horatio Nelson | Lord Nelson | Nelson Riddle | Bill Nelson | Marc Nelson | Oliver Nelson | Nelson-Atkins Museum of Art | Nelson A. Miles | Nelson Eddy | Nelson Bunker Hunt | Craig T. Nelson | Byron Nelson | Ted Nelson | William Nelson Cromwell | Nelson Piquet | Nelson County, Kentucky | Tim Blake Nelson | Nelson's Column | Nelson, Lancashire | Nelson Chai | Nelson, British Columbia | Judd Nelson | John Nelson Darby |
He was chosen by coach Nelson Acosta to play for Chile during their 2006 tour through Europe where they played the Republic of Ireland in Dublin, Côte d'Ivoire in Toulon and Sweden in Stockholm all only months before the 2006 World Cup
In January 2011, Trecco signed for Primera División club Unión San Felipe and after a successful season with the club of Aconcagua, he joined to Cobreloa in June, being runner-up of the Clausura Tournament with Nelson Acosta.
In December 2009, Carlos was acquired by Union Sports Club of San Felipe, where after a good performance, is called by Nelson Acosta, to join the ranks of Everton de Viña del Mar.