Veteran ski champion Ivica Kostelic is to once again undergo knee surgery which will sideline him for up to two months, the Croatian national ski association said on Monday. According to AFP, it will be the 10th time that the 33-year-old Croatian has gone under the knife to repair damage to his knees caused by years of wear and tear on the slopes, especially in his preferred slalom discipline. A medical examination of Kostelic's right knee, performed Sunday in Bad Ragaz, Switzerland concluded that the "flexibility of his right knee is hampered by bone and cartilage growths that have to be removed in a surgery." The surgery is being planned for April with rehabilitation expected to last up to months which would mean he could return to the slopes in July. Kostelic on Sunday won a World Cup slalom race in Kranjska Gora, Slovenia and he is currently in fourth position in the overall slalom standings. The 2011 overall World Cup winner had said he wants to continue skiing on the World Cup circuit for a further two seasons and to compete at the 2014 Winter Olympics in Sochi.