The team believes it is just a sprain, though he's expected to miss some time while he recovers.
Mike Rodak of ESPN.com added Jones is week-to-week with the injury.
Jones, 22, was a second-round pick (No. 37 overall) by the Bills in this year's NFL draft after a productive four-year stay at East Carolina. He was superb in his senior season, catching 158 passes for 1,746 yards and eight touchdowns.
He was expected to make an immediate impact for the Bills. Rodak wrote that Jones should have "the inside track for the competitive No. 2 job over free-agent acquisitions Andre Holmes and Corey Brown" alongside No. 1 option Sammy Watkins.
Production from the wideout position has been an issue for Buffalo over the past several years. Last season, with Watkins missing over half the season due to injury, Robert Woods led the team's wide receivers with 51 receptions and 613 receiving yards. The wideout group also caught just 11 touchdown passes in total.
So getting Jones reps and experience heading into the 2017 season is paramount for Buffalo, and keeping both he and Watkins healthy will be a major factor in the team improving upon a passing attack that was 30th in yards per game last season.