Anthony Ralston has returned to training ahead of Celtic’s Europa League opener against Red Star Belgrade at the Stadion Rajko Mitic on Wednesday night. After Celtic won through to the Premier Sports Cup semi-final with a 4-0 win at Partick Thistle on Sunday, Brendan Rodgers confirmed that Ralston would train ahead of the trip to Belgrade. Celtic dropped down to the Europa League after being knocked out of the Champions League qualifiers by Kairat Almaty of Kazakhstan. The Serbian outfit won the European Cup – the forerunner of the Champions League – in 1991 with a 5-3 penalty shootout victory over French side Marseille after a goalless draw in Bari, Italy. Vladan Milojevic’s side were knocked out of Champions League qualifiers this season by Cypriot outfit Pafos but their domestic form has been impressive.