Coach Dick Jauron said Monday that Johnson's ribs are very sore a day after the player was hurt in practice during training camp.
The injury is a setback to the second-year player, who was expected to compete for the team's fifth receiver spot. Johnson showed promise at the end of his rookie season, in which the seventh-round draft pick out of Kentucky finished with 10 catches for 102 yards and two touchdowns in 10 games, including one start.
Reserve defensive end Copeland Bryan limped off the field during practice with a left hamstring injury. Jauron said it was too early to determine the severity of the injury.