The Chargers, according to Popper, “wanted to bring [Johnston] along slowly.” “That plan is out the window” after the team lost Williams to an ACL injury he sustained in Week 3 against the Vikings. Popper expects Johnston to inherit the deep 50-50 balls Williams had seen in the LA offense. Without Williams, Popper said, teams will be more likely to double team Keenan Allen, who has a career day Sunday against Minnesota. Through Week 3, Johnston — a first-round draft pick — has run a route on just 29.8 percent of the Chargers’ drop backs and managed five receptions for 28 yards. Johnston should be picked up in all 12-team leagues as a volatile fantasy producer who will likely play behind Allen and Josh Palmer.