One of the feel-good stories of the NFL preseason has took an unfortunate turn. 

NBC Sports California's Scott Bair has confirmed, per a league source, that the Raiders have waived wide receiver Keelan Doss. The team hopes to sign him to the practice squad, but Doss will have to clear waivers first.

That might not be an easy task considering his preseason production and the attention paid to him on "Hard Knocks." He was highly regarded during the pre-NFL-draft process, but a pectoral injury hurt him some and he ended up going undrafted. 

NFL Media's Mike Garafolo was first to report the news.

Doss, an Alameda native and former UC Davis standout, caught 17 passes for 162 yards and scored one touchdown during preseason. 

This also means the Raiders will have a largely veteran receiver corps this season. Antonio Brown, Hunter Renfrow, Tyrell Williams and Dwayne Harris are roster locks. With Doss, Keon Hatcher and Marcell Ateman waived, per sources, the Raiders are expected to retain veterans Ryan Grant and J.J. Nelson for the fifth and sixth receiver spots. 

NBC Sports California reporter Scott Bair contributed to this report.