Lumpkin is signed off of the practice squad, to which he signed on Nov. 20, 2013. He was previously promoted to the active roster in December of last year, appearing in one game for the Raiders.
The 6-foot-4, 306-pound tackle was then waived by the team at the end of this year's training camp, before being signed to the practice squad. He previously spent time with the Cardinals practice squad after signing as an undrafted free agent in 2011.
Ausberry injured his foot against the Cardinals on Oct. 19 and has had a hard time staying healthy in his career. He has appeared in six games for the Raiders this year, posting just two receptions for 14 years. In his four years with the Raiders, he has totaled just 34 games, hauling in 11 catches for 120 yards.
General manager Reggie McKenzie also announced the signing of cornerback Jansen Watson to the practice squad to fill the open spot.
Watson was originally signed to Oakland as an undrafted free agent in May, and spent time with the team in training camp until he was waived on Aug. 24. He played four years at Iowa State, seeing action in 44 games and making 19 starts. He recorded 91 tackles, one interception, 15 passes defensed and one forced fumble. As a senior, the 5-foot-9, 177-pounder posted career highs in tackles (29), passes defensed (8) and added one interception and one forced fumble.