On his website, Tiger Woods has announced that he will miss his next tournament, the Wells Fargo Championship, due to a knee and Achilles tendon injury that arose while playing at the Masters. He states that he suffered a grade 1 medial collateral ligament injury of the knee and strained his Achilles tendon. The injury reportedly occurred while squatting to play a shot from under the Eisenhower tree off of the 17th fairway. The momentum of his swing caused him to fall backward while his foot was caught in the pine straw.

A medial collateral ligament, or MCL, injury, involves the ligament on the medial (the side closest to the body) side of the knee. It typically occurs with a valgus stress where the ankle moves toward the outside of the body while the knee moves toward the inside of the body. It’s commonly seen in sports such as soccer or football, where athletes change directions quickly or are hit on the outside of their knees. The injury can be a grade 1 injury (typically a sprain of the ligament), a partial tear (grade 2), or a complete tear (grade 3 injury).

Typically a grade 1 MCL sprain involves rest, ice, and possibly wearing a brace to prevent stress on the knee. The brace prevents any stress that could stretch out the ligament as it is healing. Typically a grade 1 sprain heals in 1-4 weeks. They almost never involve surgery. Depending on the sport, sometimes athletes can play through a grade 1 MCL sprain. Golf might be difficult as it involves a lot of twisting around the knee, which might be difficult with that injury. On his website, Woods notes that he will take some time to participate in cold water therapy and rest his knee.

Woods also notes that he suffered an Achilles tendon strain at the time of the injury, and he expects this injury to heal uneventfully as well. Reportedly Woods has been wearing a boot to protect his Achilles tendon. The former #1 golfer in the world says that he is listening to medical advice that suggested that he not play right now. “I personally contacted tournament officials and expressed my regret in not being able to play,” Woods said. “This is an outstanding event, but I must follow doctors’ orders to get better.”

Check out the Sports Injury Locator for more information on knee injuries and ankle injuries.