Nemanja Maric has expressed his frustration at the Serbia team after they suffered their seventh loss in 11 games. The Chelsea midfielder threatened to quit his national side, who were beaten 4-1 by Czech Republic in Ostrava on Friday, following a series of below-par displays and disappointing results. "I always try to lead by example but some people don't want to see that," he said, as fourfourtwo.com reported. "The attitude of some players is unacceptable, not just on the pitch but off it too and it was obvious from the moment we got together on Monday. "I told our coach [Radovan Curcic] there is no point in me carrying on with the national team if things don't change. "I'd really like to know whether some of my team mates apply the same poor working ethic at their clubs as they do in the national team most of the time." Serbia did not qualify for Euro 2016 - the third successive major tournament they have failed to make. Thinkfootballideas [@Thinkfballideas].