Filmmaker Rakesh Roshan is ready to entertain audiences once again with the re-release of his 1995 blockbuster Karan Arjun. Starring Salman Khan and Shah Rukh Khan, the film was a classic in the 90s. In a recent chat with Siddharth Kannan, Rakesh Roshan revealed that Gulshan Grover was initially cast as the villain 'Suraj.' However, Grover’s commitment to multiple projects caused delays on set.
source https://timesofindia.indiatimes.com/entertainment/hindi/bollywood/news/rakesh-roshan-reveals-why-gulshan-grover-was-immediately-replaced-by-aasif-sheikh-in-karan-arjun-for-an-11-am-shoot-he-would-show-up-at-4-pm/articleshow/115497943.cms
source https://timesofindia.indiatimes.com/entertainment/hindi/bollywood/news/rakesh-roshan-reveals-why-gulshan-grover-was-immediately-replaced-by-aasif-sheikh-in-karan-arjun-for-an-11-am-shoot-he-would-show-up-at-4-pm/articleshow/115497943.cms