Real Madrid, Paris Saint-Germain, Bayern Munich and Juventus have all opened talks with Antonio Rudiger’s representatives over a pre-contract agreement this month. Ralf Rangnick, the Manchester United interim manager who will take up a consultancy at Old Trafford in the summer, is also an admirer of Rudiger and knows the Chelsea defender’s brother – who is also his agent – well. Rudiger’s Chelsea contract expires at the end of the season and he is now free to discuss a deal with foreign clubs ahead of a free transfer in the summer. Chelsea remain keen to extend Rudiger’s contract and remaining at Stamford Bridge has not been ruled out by the Germany international’s camp. Please use Chrome browser for a more accessible video player FREE TO WATCH: Highlights from Chelsea’s draw against Liverpool in the Premier League However, the Blues’ most recent offer – made at the start of the season – was dismissed by Rudiger and his representatives as it promised to pay him only half...