Smith announced his retirement from the NFL on Tuesday.
Smith played four offensive snaps but didn't record any counting stats during Sunday's 30-20 loss to the Saints.
Smith (back) was a full participant at Tuesday's practice.
Smith (back) has been ruled out for Sunday's game in Dallas, Michael Rothstein of ESPN reports.
Smith (back) is listed as doubtful for Sunday's game against the Cowboys, Scott Bair of the Falcons' official site reports.
Smith (back) was listed as a non-participant in Wednesday's practice, Michael Rothstein of ESPN.com reports.
Smith caught all three of his targets for 30 yards during Sunday's 27-20 win over the Jets.
Smith caught all three of his targets for seven yards and one touchdown during Sunday's 17-14 win over the Giants.
Smith was placed on the reserve/COVID-19 list Tuesday, Tom Pelissero of NFL Network reports.
Smith was traded to Atlanta for late-round draft compensation Tuesday, Adam Schefter of ESPN reports.