The skill set that the Packers lack in the receiving corps is yards after the catch ability. They need a player who can win in the short game and make plays with the ball in their hands.
In 2018, Randall Cobb averaged 6.5 YAC per reception, which was actually 7th among all WR's.
Cole Beasley managed 3.4 YAC per reception, which is too far down the list for me to actually figure out his ranking.
Jamison Crowder was 4th in this category among wideouts at 7.6 YAC per reception. He would be an ideal FA target. Adam Humphries wouldn't be a bad, younger option either (5.7 YAC per reception) as a consolation prize.
Albert Wilson of the Dolphins averaged an absurd 12.9 YAC per reception on 35 catches last year. He is entering the 2nd year of a three year deal with the Dolphins (3/24). With the regime change, if they would accept, say, a 5th round pick for him, I would take that trade all day.