So when playing zone, it's about using length to make plays on the ball. But when asked to man up, in many situations, CBs in this scheme are manned up on WRs that are split wide and near the sideline. When a WR is lined up near the sideline like this, there are a very limited number of routes they can run (Go/Fade, Deep Out/Curl, Post) - all routes up the sideline.
We've discussed the Cover3 'Mable' call and how one CB will be playing man while everyone else on the field is playing Cover3. That CB manned up is often defending a lone WR on the weakside, split wide outside the numbers. RCB (bottom of screen) manned up while everyone else playing Cover3.
