By Jude Summerfield Barcelona continue their bid to rival Real Madrid for the La Liga title on Tuesday night when they visit Rayo Vallecano. The Blaugrana have won their opening two games to sit behind only Real Betis on goal difference in Spain’s top flight, securing 2-1 victories over Valencia and Athletic Club to help Hansi Flick make a successful start to his stint in charge. They take on a similarly unbeaten Vallecano, who have made headlines in recent days by bringing in 2014 World Cup star James Rodriguez on a free transfer. Here’s 90min’s preview to Tuesday night’s La Liga clash. What …