Moss was added to the Patriots' injury report Friday.
While both Welker and Moss were present for the start of practice Friday -- for stretching and kickoff return drills -- neither took part in the team-drill portion of practice.
Veteran cornerback Shawn Springs (knee) and rookie cornerback Darius Butler (thigh) were also added to the team's injury report on Friday. Both are questionable and had limited participation in team drills.
Also, Patriots coach Bill Belichick said that newly acquired linebacker Prescott Burgess could suit up for the game despite being part of just three Patriots practices.
"Prescott has been in a pretty sophisticated system," Belichick said. "I'm not saying we're the Ravens, but they do a lot of different things. He's working hard with [linebackers coach] Matt [Patricia] and [special teams coach] Scott O'Brien to pick things up. He's doing that."
As expected, the Patriots ruled linebacker Jerod Mayo (right MCL) out for the game.
Tight end Chris Baker (ankle), center Dan Connolly (back), receiver Julian Edelman (ankle), safety Brandon Meriweather (ankle), safety Matthew Slater (elbow) and cornerback Terrence Wheatley (knee) were all listed as questionable, while quarterback Tom Brady (right shoulder) was listed as probable.
For the Falcons, running back Jerious Norwood (head) is the primary concern. He is questionable and has not practiced all week.
Mike Reiss covers the Patriots for ESPNBoston.com.