The Portugal star reached the 50-goal mark for the third straight season in Real Madrid's 3-0 win over Athletic Bilbao last Sunday and is on his way to eclipsing last campaign's haul of 60 goals. Ronaldo has found the net in his last eight matches and will be a central figure in the Champions League semi-final clash with Borussia Dortmund in midweek.
The 31-year-old forward scored scored his 17th goal of the season in the 3-3 draw with Sevilla and is Real Betis' top scorer in all competitions. Castro will be out to get on the scoresheet again and fire Betis towards the European qualification spots.
Madrid will aim to continue their rich vein of form and some of their fringe players will hope to perform well and force themselves into the reckoning for the Dortmund game. Betis are a decent side going forward but their recent away performances, bar the 5-1 win over Andalusian rivals Granada, have been poor.