Thrust into the role as the top target on the Green Bay Packers in 2015 after the ACL injury to Jordy Nelson, Randall Cobb had his worst season (aside from injury) in terms of efficiency and effectiveness. Horribly miscast as a primary receiver, Cobb struggled to find space and separate from double teams. He may also have been battling a shoulder injury from the preseason that limited his performance.
As a result, Cobb's efficiency was cut almost in half from his career totals, and his 0.53 Reception NEP per target was 29th (out of 32) for receivers with 100 targets. His yards per reception dropped from 14.1 in 2014 to a Jarvis Landry-like 10.5 in 2015, and his touchdowns plummeted from 12 to just 6 despite seeing a career high in targets.
After finishing as the WR6 in fantasy scoring in 2014 (Nelson finished as the WR2), Cobb was being drafted in the early second round last season but fell to the late third this year. Instead of seeing Cobb's disappointing 2014 season as an aberration, fear over Jordy's return to prominence or Cobb's ability to replicate his 2014 season have kept his value deflated.
While it's true that an ineffective Nelson could jeopardize Cobb's ability to reach his former potential, we've seen Cobb produce (both yards and touchdowns) as the clear secondary target in this offense, and Aaron Rodgers is still one of the best quarterbacks in football.
Cobb's efficiency in every year prior to 2015 was outstanding and indicative of his ability when cast correctly as a secondary option who can work the middle of the field.
If you are low on Cobb because you worry about Nelson's health, durability, and effectiveness, then fine. But if you believe Nelson will return to form in 2016, there is no reason to doubt Cobb's ability to produce alongside him.