Justin Blackmon has been suspended indefinitely and will not be eligible to return until the start of the 2014 regular season. This is because of a violation of the league's substance abuse program. This means that he can be dropped from your FFL team.
In his place, you should pick up Mike Brown who is currently the 3rd wide receiver for the Jaguars. He caught 12 passes for 212 yards and 1 TD in the past 3 games. He should be seeing a lot more targets as he gets bumped up to the #2 WR.