Williams is expected to be ready for the Chargers' regular-season opener against the Bengals on Sept. 13, according to ESPN's Adam Schefter.
A source told Adam Schefter that Williams does not need surgery. The source would be "shocked" if Williams did not play in Week 1.
Williams' injury was first reported Monday by NFL Network.
Williams suffered the injury when he landed on his shoulder after attempting to make a diving catch.
The 6-foot-4 Williams had 49 catches for 1,001 yards -- both career highs -- and two touchdowns last season.