Bynes was cut from the roster Tuesday, but returned Wednesday night after clearing waivers to pick up his iPad and was re-signed to the practice squad.
The Ravens cut rookie defensive tackle A.J. Pataiali'i to create a spot for Bynes on the 10-man practice squad.
Although Bynes has played in 26 career games with nine starts and was on the Ravens' practice squad in 2011 and 2012, he's eligible for the practice squad under the NFL's expanded rules adopted this year.
Bynes started six games last season at inside linebacker and played in all but one game as he recorded 45 tackles and three pass deflections.
"All I can tell you about Josh Bynes is if we can ever bring him back, we will in whatever capacity we can," Ravens coach John Harbaugh said Tuesday when Bynes was released. "He's been a Raven through and through. He's done nothing but help us be our best. He's completely all-in for everything we've ever done here. I love Josh, and I know he'll do well no matter what he does."