Evidence has to work on his quickness off the line & become more physical to be a regular in the rotation...
Gotta have quickness off the line to have success on underneath routes (which is the case for all receivers), and having that opens your game up as it makes the CB respect your ability!
**If a receiver has limitations at the LOS, a good CB will quickly capitalize on that weaknesses, limiting you to being a one trick pony. This typically hapens to tall lanky WR's that aren't physical players (think Tommy Streeter - not serviceable underneath).
It's not the case with all Tall WR's, just the lanky long striding tall guys. For instance, the difference with Evidence Njoku and Lawrence Cager is the body type! Cager moreso has a long torso/shorter lower body - which helps him in the area of having quick feet.
Now, if a long strider is physical (Terrell Owens) that helps, but if not, at best you're limited to being a Hail Mary guy, or someone you plug in as a run blocker...and when the running game is clicking, you can hit him on some play action passes...
-- Or the coaching staff can start Evidence Njoku, and simply throw him some regular 10 yard jump balls!