Real Madrid legend Zinedine Zidane has revealed that Real Madrid are keeping track of Liverpool and England forward Raheem Sterling. Madrid have long been linked with the 20-year-old and now Zidane, currently managing Castilla, Madrid's second team, has gone on record to say the European champions are keeping tabs on the youngster. "We know who Raheem Sterling is, and of course we are monitoring him as a player," Zidane told the Daily Mail. "There are very few players in the world who can improve the Real Madrid squad, so it is going to make sense we monitor the progress of the best young players in the world." Sterling says he will not put pen to paper on a new Liverpool contract and puts his decision down to a desire to win trophies, and not for more money. He would be handed guaranteed Champions League football at Madrid but he would also face tough competition for places as things stand at the Santiago Bernabeu. Sterling still has a contract at Anfield until 2017 and Liverpool boss Brendan Rodgers says he has no plans of selling the player just yet. Madrid may have to bide their time to get their man, as they did to sign Gareth Bale for a world-record fee from Tottenham Hotspur. "We monitored Bale for over a year, the same with Isco and also Varane," Zidane added. “We monitor many of the best young players in Europe, then if we feel they have something to offer Real Madrid we will contact their club and try and make the next step." Premier League pair Chelsea and Manchester City are also reported to be interested in Sterling, who has scored six goals and provided seven assists for Liverpool in the league this season.