Scan more than once. Take an early look as the ball travels, then look again as it arrives, and play the option that is free at the moment you release it rather than the one you saw first.
Same setup as the base drill, but add a second defender who starts deeper. As the ball travels to the middle player, the defenders switch which target they are covering, late enough that a single early scan gives the wrong answer. The receiver must look again before releasing. Vary whether the switch happens at all, so he cannot simply assume it will.
Information decays. The picture a player took a second ago is already wrong by the time he touches the ball, because in that second a defender has slid across, a teammate has moved, and the option that looked free has been closed. Players who scan once and then execute what they saw are playing the previous version of the game, and it is a specific, common and correctable error.
So the instruction is to look twice: early as the ball starts travelling, and again as it arrives. The first look tells you what is likely. The second tells you what is true. Coaches almost always teach the first and stop there, which produces players who are aware and still play into pressure.
The late switch is the clearest example. A player sees a free man on the far side, commits to that pass, and by the time it leaves his foot the whole block has shifted and the receiver is marked. The same player, looking again on arrival, either releases it a beat earlier or plays the option that has opened nearer to him.
Which puts a demand on the first touch that is easy to miss. It has to stay neutral, meaning it commits the player to nothing and keeps both options live. A touch that opens hard to one side has already chosen, and the second scan then has nothing to change.
The honest difficulty is that this is genuinely advanced. Players who are still learning to scan at all will not manage two looks, and asking for it too early produces hesitation rather than awareness.
Save it to your private drills, then change the animation, adjust positions, swap equipment, or drop it into a session block. Or start from a blank pitch and build your own.