They don’t necessarily know if it’s faked at the time. Players come off the field for treatment all the time.

> This is way beyond the norm in soccer

This is just false. And coming off the field doesn’t require a substitution.

The difference is your team can be down to 10 men for that period so you’re not likely to want to fake it and leave your team short.

They do sometimes get taken off the field for treatment and are then allowed back on. It’s not automatically a substitution.