Cape Town - Jacques Kallis, arguably South Africa's best-ever all-rounder, believes JP Duminy can fulfil this role with aplomb for the Proteas' Test side in future.Kallis, a 162-Test veteran, has amassed 13 128 runs at an average of 56.10 and claimed 288 wickets at 32.43.Despite being 37, Kallis's flame is not out just yet, but he has struggled with injuries in recent years and the Proteas should start preparing for when he's not around anymore.And Kallis believes a man that could play a vital all-rounder role when he's not around is his Cape Cobras team-mate Duminy.Duminy was mainly considered as a part-time spinner at the start of his career, but has performed a more than adequate role for the Proteas in recent times, especially in limited-overs cricket.The off-spinner has taken only 12 wickets (at an average of 42.50) in 17 Tests but Kallis feels he could play a more important role with the ball in future.In an interview with the Cape Times, Kallis said Duminy can become a "fully-fledged" all-rounder in the Proteas' Test side."He certainly has the potential and talent to succeed. He is a top batter and bowls more than useful off-spin. If he really works on his bowling, and puts the effort in, he can easily bowl 10-15 overs a day that is required from a top-class all-rounder. I really think JP can do it," said Kallis. Duminy has scored 789 runs in Tests at an average of 37.57.The Proteas next Test is against Pakistan in Abu Dhabi from October 14.