UEFA Champions League Semifinal 2nd Leg: TodayBarcelona vs Chelsea 20:00 SS3MADRID – Barcelona coach Pep Guardiola is in danger of tarnishing his reputation as the man with the Midas touch when the holders seek to overturn a 1-0 deficit against Chelsea in Tuesday’s Champions League semi-final second leg at the Nou Camp.The 41-year-old former Barca and Spain midfielder has inspired the Catalan club to an impressive 13 trophies since he took charge in 2008, including three straight Spanish league titles and Champions League triumphs in 2009 and 2011.However, elimination from Europe’s elite club competition would be a fresh blow following Saturday’s 2-1 La Liga reverse at home to Real Madrid which put their bitter Spanish rivals seven points clear at the top with four games left.Real could get another crack at Barca in next month’s Champions League final if they manage to get past Bayern Munich, who are seeking to protect a 2-1 lead from last week’s first leg when they play at the Bernabeu on Wednesday.Guardiola suffered the rare embarrassment of having to explain why his tactics failed against Real after he left Cesc Fabregas, Alexis Sanchez and Pedro out of his starting lineup and gambled on 20-year-old B-team winger Cristian Tello.The pacy Tello showed flashes of promise but wasted one of Barca’s best chances with a wild effort, while Sanchez scored immediately after coming off the bench.Fabregas had scant opportunity to demonstrate the creativity and eye for goal that Barca paid Arsenal 40 million euros for when he replaced Tello with only 10 minutes left."If I had left other players out you would probably be asking me now why I did not include them,” a defensive Guardiola told a post-match news conference.