Cape Town - David De Gea is relishing his difficult job as United's number one goalkeeper and insists the defensive changes are making him a better player.The Spanish goalkeeper has played behind several defensive combinations with Chris Smalling, Jonny Evans, Tyler Blackett, Paddy McNair, Daley Blind, Michael Carrick and Marcos Rojo all doing duty at centre-back this season."It obviously makes things very difficult," De Gea told the club's official website."but that’s football and it’s my job to be able to adapt to different situations. "As a goalkeeper it’s important to form a good understanding with your back four and become familiar with each other’s positions on the pitch. "It’s difficult when the players aren’t there but you have to adapt and concentrate on your job. The experience has definitely helped me improve.De Gea believes with hard work and concentration on their own game, Manchester United can continue to rise up the English Premiership table. "Manchester United is a huge club and will always be there or thereabouts."In terms of the league table and the position we’re in we are not far away. "All we can do is work hard and try to keep improving and it’s important that we completely concentrate on ourselves and not look too much at others."