Halfway through December, the Lions' secondary was decimated by injury and COVID-19, and they claimed Smith off of waivers to help add depth to a battered group. Smith never played a defensive snap in Detroit, but he was an immediate special teams contributor in Weeks 14, 15, and 16. Unfortunately, as the Lions' secondary returned to health, Smith saw his opportunities (snaps) decline each week, and last week he didn't see the field in any capacity.
With 11 healthy defensive backs on their active roster and another three on the practice squad, keeping Smith on the active roster was a bit of a luxury at this stage and he was released.
While no corresponding move was announced at this time, the Lions do have an obvious hole on the roster this week as the team placed both starting offensive tackles—Taylor Decker and Penei Sewell—on the reserve/COVID-19 list. Promoting a practice squad offensive tackle is purely a speculative move at this point, but it would follow a pattern this staff has previously followed.
The Lions, of course, could also use the vacated roster spot to sign a player for logistical reasons, as teams often do just ahead of their offseason. If the Lions were to sign a player from the practice squad to the active roster, they could give him a contract that would help ensure he stays with the team during the 2022 offseason.
For example, if the Lions wanted to retain UDFA rookie linebacker Tavante Beckett, they may sign him to the active roster.
On Sunday the Lions' regular season will conclude, and come Monday, all members of their practice squad, including Beckett, are set to become “Street Free Agents” (SFA). That means they are eligible to sign a “futures contract” (a 2022 contract that doesn't count against the salary cap until March) with the Lions or they can leave for a new organization. Although, if the Lions sign a practice squadder to the active roster, they can simply give him a deal that extends into 2022 (a common practice) or sign him through the end of the season (basically 24-48 hours) and then his offseason designation would change (from SFA) to an Exclusive Rights Free Agent (ERFA), meaning he can only sign a 2022 contract with the Lions.
So what will the Lions do with the open spot? It’s hard to say for certain, but we will probably find out in the next 48 hours.