The Rams waived Sumpter (undisclosed) on Wednesday with a non-football injury designation, Myles Simmons of the team's official site reports.
An undrafted free agent out of Kennesaw State, Sumpter caught 21 passes for 316 yards and four scores in his final season of college. He'll be available off waivers to any of the league's 31 other teams but could revert to the Rams' injured reserve list if he goes unclaimed.
Sumpter officially signed a contract with the Rams as an undrafted free agent, D. Orlando Ledbetter of The Atlanta Journal-Constitution reports.
Sumpter caught 21 passes for 316 yards and four touchdowns in 2018 for Kennesaw State. He will face an uphill battle for a roster spot on the Rams' crowded wide receiver depth chart.