Ordinarily, there is pretty minimal risk of losing players to the waiver wire in the middle of the season, especially when it comes to players with basically no playing experience, like rookie or first-year undrafted free agents.
The Pittsburgh Steelers are doing a bang-up job of bucking that trend and defying the odds in that regard this year, as, since the final 53-man roster was made, they have had no fewer than three players, all undrafted free agents who had never played in a game before, claimed off waivers.
First to be claimed was wide receiver Diontae Spencer, who was undrafted several years ago but never caught on in the NFL.