San Francisco 49ers linebacker Dre Greenlaw appeared to suffer a game-ending injury while running back onto the field at the Super Bowl. Greenlaw was seen bouncing up and down on the sidelines as he waited to get back on the field after a San Francisco punt. As the 49ers defensive unit rushed onto the field, Greenlaw’s left leg appeared to get stuck in the ground. The 26-year-old then went down in a heap and looked in agony and his team-mates had their head in their hands. Medical staff attended to Greenlaw, but he looked in some discomfort on the sidelines. CBS reported that Greenlaw was unab…