Celtic winger Yang Hyun-jun believes he has staked his "entire footballing career" on helping South Korea win the Asian Cup - he will receive an exemption from military duty if they lift the trophy for the fourth time in a row - as it meant the 24-year-old missed crucial games with the Scottish champions. Celtic are relaxed about holding on to Benjamin Nygren next summer despite the 25-year-old Sweden midfielder having admitted there was plenty of interest during the last transfer window. Celtic have shown negligence by failing to nurture a successor to captain Callum McGregor as the 33-year-old midfield general nears the end of his contract, according to former Aberdeen chief executive Keith Wyness.