Scottish Premier League leaders Rangers have confirmed today that Steven Naismith will miss the rest of the season with anterior cruciate ligament damage. Scotland international Naismith, 25, suffered the injury during Rangers\' 2-1 win at Aberdeen on Saturday, a result that left the Glasgow club nine points clear at the top of the table. \"Steven will be treated by the same surgeon who successfully treated him in 2008 and his rehabilitation programme will be 8-9 months,\" read a statement on Rangers\' official website. Naismith has scored nine goals in 11 matches and his manager Ally McCoist admits the news is a major blow. \"He was in the form of his life and it is a huge blow for him and the club that he is out for the rest of the season,\" McCoist said.