The 21-year-old stopper is currently on his third successive loan spell at the La Liga leaders, who can boast the best defensive record out of the 20 sides. Courtois has also helped his side to the quarter-finals in the Champions League, holding Barcelona to a 1-1 draw at the Nou Camp. Question marks surround the Belgium international's future at Stamford Bridge, having never featured for his parent club since joining from Genk in 2011.