Suppose yesterday is not Sunday. Which of the following days cannot be the day after tomorrow?

Let's logical evaluate the condition:
1. If yesterday is not Sunday, then today cannot be Monday ($\text{Sunday}+1\text{ day}$).
2. The day after tomorrow corresponds to ($\text{Today}+2\text{ days}$).

Let's verify the options to check what happens if each day is assumed to be the day after tomorrow:

* If the day after tomorrow is Wednesday, then today must be Monday ($\text{Wednesday}-2\text{ days}=\text{Monday}$).
* However, we already verified that today CANNOT be Monday.

Thus, the day after tomorrow can never be Wednesday under these conditions.