I think Odell Beckham Jr could have a big year, but he's valued pretty low right now due to recent injuries. The Ravens are paying him a lot of money, so I'd expect them to use him. His knee seems to be fully healthy now. He was great on the Rams but admitted he played with a messed up ACL the entire time (until it fully blew up in the Super Bowl), so now that he got proper surgery and is in better shape, I wouldn't be surprised if he performed better than he did for the Rams.
Some deeper sleepers are guys like Richie James, Parris Campbell, Tutu Atwell, Michael Wilson, Trey Palmer, and Bryce Ford-Wheaton. All guys that you can get for cheap or really late who could potentially be flex-worthy this year.
Who are some of your sleeper picks for the upcoming NFL season?