The San Antonio Express-News (Jeff McDonald) reports: Even before Manu Ginobili went under the knife, Roger Mason Jr. expected to find himself under the preseason microscope. The former Washington Wizards swingman rates as the Spurs’ most notable free-agent acquisition of the offseason. With Ginobili out, Mason — who averaged a career-high 9.1 points last season — will get plenty of time in the preseason to show his stuff. How quickly he can grasp the Spurs’ system will go a long way toward determining how the Spurs fare without Ginobili.