WATCH: Costa, Iniesta, Ramos and De Gea train with Spain ahead of last-16 World Cup match with Russia

Diego Costa, Andres Iniesta, Gerard Pique and Sergio Ramos were among the Spain players taking part in training on Wednesday as they prepare to face host nation Russia in the last 16 on Sunday. Manager Fernando Hierro held a session at the team base in southern Russia, with some of the players' relatives watching on from the stands. Spain are expected to fly to Moscow on Saturday where they will train one last time before the referee blows his whistle to start the game at the Luzhniki Stadium on Sunday at 6pm UAE time. David de Gea also took part in the session. The Manchester United goalkeeper has been heavily criticised by the Spanish media for his performances in the group stage, most notably for a mistake that led to Cristiano Ronaldo's second goal in a 3-3 draw with Portugal in their opening Group B match on June 15. However, he is likely to keep his place in the starting XI for the Russia match, with Napoli's Pepe Reina remaining his understudy. ________________ Read more on World Cup 2018: World Cup 2018: Day 15 updates - Germany out, England take on Belgium WATCH: Messi sits out training as Argentina prepare for World Cup clash with France Spain claim late draw against Morocco to snatch World Cup Group B top spot Spain rally behind De Gea as questions swirl over goalkeeper's form ahead of crunch Iran World Cup match