Chairman of selectors Ajit Agarkar on Saturday conceded that the void left by the Test retirement of premier cricketers Virat Kohli and Rohit Sharma is tough to fill, but hoped that other players will step up during the upcoming tour of England. Rohit was the first to announce retirement from Test cricket on May 7, while his long-time teammate Kohli followed suit on May 12. "When guys like that retire, they are stalwarts of cricket...it is always difficult, (their) shoes are very big to fill. But one way of looking at it is, that it's an opportunity for others," Agarkar told the media after announcing India's 18-member squad for the five-Test series starting June 20.