What goes into an NFL trade?

It's a question I feel like I'm answering all the time. Every time someone says "The San Diego Chargers should trade Donald Butler, he's a bum" it's up to me to tell them why it's not quite as simple as sending one player to another team in exchange for another player or picks.

Typically, there's very little difference between releasing a player and trading a player. Certain contracts have little clauses built in them that create differences, but those are rare and still don't help very much.

For the Chargers to trade Eric Weddle, which is something that many people have suggested since it doesn't appear he'll be happy this year or be a Charger next year, they would first need to take $2.6 million dollars and light it on fire. Kind of.

If they were to trade or release Weddle, the Chargers would be on the hook for the remainder of Weddle's signing bonus ($2.6 million), but would rid themselves of his salary this season ($7.5 million), leaving them with a net gain of $7.5 million in cap space. With that $7.5 million, they would be hoping to replace a 5-time All Pro.

One of the more interesting names thrown out as a possible trade target for the Chargers would be Muhammad Wilkerson of the Jets. Not only is he a monster defensive lineman with experience in a similar defense, but he's 25-years old and in the last year of his contract.

Wilkerson wants a mega deal and the Jets aren't prepared to give him one. Sound familiar? Now, the Chargers might be even less willing, since they just gave a big deal to Corey Liuget to be the anchor of the line, but who knows? Perhaps they want to build the league's best offensive and defensive lines, stocked with players in their mid 20s, and try and win a Super Bowl that way.

The fun thing is, it wouldn't cost the Jets a dime to trade Wilkerson. They would just be on the hook for Weddle's $7.5 million, but that's not far off from the $7 million they're about to pay Wilkerson already. Net loss of a half-million and they get all season to negotiate with Weddle? That's worth it to me, if I'm the Jets.

If the Chargers swung the deal, they'd end up with about $1 million less in cap space than they have now ($9.4 million), but they'd be replacing one All-Pro with another and would be building their defense up so much in the front-seven that the drop off from Weddle to Jimmy Wilson would probably be tolerable. They would also get a player in his mid 20s that they could book-end with Liuget for the next 4-5 years, if they were willing to shell out the money.

What do you think the Chargers should do?