By Matt Hladik Golfer Phil Mickelson reportedly has more to worry about than the continued fallout from his comments regarding the Saudi Golf League. According to ESPN’s Mark Schlabach and Kevin Van Valkenburg, people close to Mickelson say he is “concerned” about an upcoming memoir from sports gambler Billy Walters, co-written by Armen Keteyian. Walters was sentenced to jail time in 2017 for conspiracy, securities fraud and wire fraud. Though he has since been released, Walters reportedly blames Mickelson for his punishment, according to Action Network’s Darren Rovell. “The story goes that Mi…