The gap that appears after a defensive substitution

Watch how the distance between midfield and defence changes when a team brings on a central defender late in a match. I saw this in a recent Serie A game. The substitute often takes time to read the pressing triggers, and the line drops slightly deeper to protect itself.

That extra two or three metres creates space for the opposition's number ten. The passing lane into that zone opens up because the holding midfielder now has to cover more ground. Full-backs get caught between stepping out and staying compact.

The first ten minutes after a substitution tell you more than the pre-match shape. Watch where the second balls land. That space between the units is where the next chance comes from.

The substitution changes the shape, not the scoreboard. Watch the distances.

Question: How do you adjust your read when a centre-back comes on late and the defensive line drops?