Smith (undisclosed) was waived by Detroit with an injury settlement Wednesday.
Smith's (neck) contract with the Lions' practice squad expired Monday, per the NFL's transaction log.
Smith suffered a concussion during Sunday's 29-0 loss to the Patriots, Tom Pelissero of NFL Network reports.
Smith was transported to a local hospital to be evaluated for a neck injury sustained during Sunday's game against the Patriots.
Smith was waived by Seattle on Monday.
The Seahawks have claimed Smith off waivers from the Cowboys, Mike Garafolo of NFL Network reports.
Dallas signed Smith to a reserve/future contract Monday.
The Cowboys placed Smith (hand) on the practice squad injured reserve list Saturday, Michael Gehlken of The Dallas Morning News reports.
Smith returned to the game after suffering a broken hand in Sunday's 31-10 win over the Bengals, Ian Rapoport of NFL Network reports.
Smith was signed from the practice squad by Dallas on Saturday, Rob Phillips of the Cowboys' official site reports.