Smith has been sidelined with a torn triceps since Oct. 24, but the Steelers didn't place him on season-ending injured reserve in the hopes that he would recover in time to help the team during the playoffs.
With the AFC Championship Game against the New York Jets just five days away, Tomlin said if Smith is active, he likely will play a limited number of downs.
"Snap count is probably going to be part of that discussion," Tomlin said, but he added that "it would be nice to add that tool to the toolbox."
A source with knowledge of the situation told NFL Network insider Jason La Canfora last week that the Steelers might not have Smith back unless they reach the Super Bowl.
Smith has 44 sacks in his 12-year career, all with Pittsburgh.