^ Marin was injured half the time he was here (them jammy hammies). Besides, it was a sort of contingency purchase in case we failed to qualify for the CL and missed out on Hazard & Oscar. He almost got sent off with his first action of the game, lunging into an opposition player as soon as he came on. Did himself no favours with his displays. I had high hopes for him, but what can you do if a player is unable to get match-fit? The loan to Sevilla should give him lots of playing time as they need to replace Jesus Navas.
As for Courtois, there is a plan for him to come back to Chelsea next year. Mourinho wanted him this year to compete with Cech, but 2014 being a World Cup year, he needed time as the #1 keeper in order to represent his country. He is the future Chelsea #1.
Also watch out for KDB - Kevin De Bruyne.