The Atlanta Falcons have lost wide receiver Julio Jones for the year and will be without Roddy White for at least Week 7, so quarterback Matt Ryan has very few people to throw to. With Harry Douglas stepping in to a bigger role, the team needed to add some depth and they provided that by making the decision to promote Darius Johnson from the practice squad.
From Vaughn McClure of ESPN.com:
League source tells me Falcons will promote rookie WR Darius Johnson from the practice squad to add depth, fill open roster spot
— vaughn mcclure (@vxmcclure23) October 19, 2013
Johnson is a rookie out of Southern Methodist who spent time with the Falcons during camp and the preseason, so they are familiar with what he can offer on the field.
It is unlikely that Johnson will be on the field for a lot of the reps on Sunday, but he could get the call a few times and impress the coaching staff enough to earn a larger role moving forward.