Why isn’t this possible...

[Sled21]

You asked why it wouldn't work, and there are reasons. For instance, you say you want to dump Eifert because you are tired of him not being on the field, so you want to trade him for Glenn. For that to happen, the Bills have to want Eifert, who is never on the field. The reasons you, or anyone, wants to trade a player are the same reasons other teams won't want them. Money being the exception.