Just as the Chargers are making a serious push to do something no non-Chargers team has done since the AFL-NFL merger — make the playoffs after starting 0-4 — their first-round pick has encountered familiar trouble. Mike Williams left Thursday’s game with a knee injury, and while this is a different malady than the back ailment that shelved the talented pass-catcher for much of the offseason and into the early portion of his rookie slate, Ian Rapoport of NFL.com reports (on Twitter) the team is concerned about Williams’ setback. Williams will undergo an MRI on Friday, per Rapoport, who adds the Chargers are worried he will miss game time.