Manchester United legend Rio Ferdinand has been really impressed with one former Chelsea player this season. Chelsea have sold and lost a lot of good players recently. For example, they sold the likes of Kai Havertz and Mason Mount to Arsenal and Manchester United respectively last summer. The summer before that, they also lost Antonio Rudiger and Andreas Christensen on free transfers. Rudiger joined Real Madrid in a move that has quickly paid off. In only his second season at the club, the central defender has already won the La Liga title and now the Champions League following his side’s 2-0…