Phil Mickelson leads by four shots after the Valero Texas Open third round . The 36-year-old is on nine under par , four shots ahead of Jordan Spieth . Five-time major champion Jimmy Walker is on level par .
Jimmy Walker leads by four shots after the Valero Texas Open third round . The 36-year-old is on nine under par , four shots ahead of Jordan Spieth . Five-time major champion Phil Mickelson is on level par .