The Gregorian calendar turned to April today while at the same time the more important (for our purposes) NFL calendar turns to draft season.

While folks with nothing else to do and Greg Jennings are busy playing April Fools jokes, NFL folks are thinking draft needs, and draft picks, and draft visits, and Pro Days and draft day trades.

On the draft visits, the Dolphins have set up visits, as I reported two weeks ago, with wide receiver DeVante Parker, while USC's George Famer and Auburn's Sammy Coates are also on the visit schedule, as Barry Jackson noted. UM's Phillip Dorsett and FSU's Reshad Greene are also visiting during local visits, as expected.

Check out Barry's blog for other lesser scheduled visits.

Today we cover the draft day trades issue.

Two issues that continually arise in my text exchanges and conversations with NFL sources is the possibility of a Dolphins trade to acquire either a veteran guard or cornerback or both right before or during the draft.

Yes, the Dolphins are likely to draft a cornerback. But what if the cornerback they covet in the first or second round are gone?

That's where the shopping for a veteran CB would be happening.

The Eagles, who one source tells me are willing to trade just about anybody for the right compensation, are said to be willing to trade cornerback Brandon Boykin. I cannot independently confirm Boykin is on the market, but other "reports" say he is.

Boykin has been a more than functional nickel cornerback for the Eagles since being drafted in 2012 but he was picked by former coach Andy Reid. Current coach Chip Kelly inherited him. And no player Kelly inherited should feel comfortable about their long-term status in Philly.

So Boykin's on the radar as a possibility.

And what might the Dolphins give in return?

Well, forget Dion Jordan for the time being. A source told me during the NFL owners meetings that trading Jordan was "highly unlikely," because of the salary cap issue involved, the idea that no one would give enough compensation to get him based on his limited contribution, and the idea that the kid does have something of a future in Miami's vision.

What does that mean?

For cap purposes it would actually cost the Dolphins more against the cap for them to trade Jordan than keep him. That's right. Having Jordan on the roster is cheaper than moving him -- a difference of $5.61 million if Miami keeps him versus $6.67 million if they trade him.

So while the Dolphins would not necessarily be unable to carry the extra $1 million in cap charge to move Jordan, you must consider it would mean carrying that extra charge for moving him added to the $5.6 million it costs to keep him, added to the charge a new player or draft pick the Dolphins would be getting also brings.

It adds up.

Jordan has done practically nothing in Miami the past two seasons considering he was he No. 3 overall selection in 2013. He's been suspended not once but twice by the NFL -- once for performance enhancing drugs, once for recreational drugs. He was injured much of his rookie season.

Dion Jordan has, frankly, been a disappointment.

But the potential continues to titillate fascinate.

Jordan can run step for step with New England tight end Rob Gronkowski. Indeed, he covered Detroit wide receiver Calvin Johnson near the end of the game in key situations last season. He is a pass rush threat. He can be great in the right environment and if he gets his act together.

There is also this: The Dolphins' situation at defensive end seems solid now. Cameron Wake and Olivier Vernon are the starters. Jordan and Derrick Shelby are the backups along with Terrence Fede and others.

But ...

Wake is 33 years old. He has two more years, including 2015, left on his contract. Despite his continued production, he is no longer the long-term answer at defensive end for the Dolphins.

Olivier Vernon, meanwhile, is in the final year of his contract. He plans on having a big season. Then he plans on getting at least $10 million a season on his next deal either from Miami or someone else. And that may be conservative.

Shelby is also on a one-year restricted free agent tender. He expects to hit free agency after this season as well.

There is no way the Dolphins will have all three players -- Wake, Vernon, Shelby -- on the roster for 2016.

But Jordan, all of 25 now, will be in the final year of his rookie contract in 2016. His role then could be as the primary backup behind Wake and Vernon. Or he could be a starter.

So keeping him and having him learn to be a fine defensive end has some value to the Dolphins.

That and the dead money significance of trading Jordan makes moving him an iffy proposition. The Dolphins would have to be seriously motivated by the proposed compensation to trade Jordan.

There is, obviously, a possibility the Eagles may want to move up from their No. 20 draft spot to get to Miami's No. 14. There is, obviously, the possibility giving up No. 14 for No. 20 in the first round plus Boykin makes sense if the receiver or cornerback the Dolphins covet at No. 14 is gone. Keep that in mind.

Finally, the Dolphins have been linked, erroneously according to the Dolphins, to guard Evan Mathis of the Eagles. (Yeah, that team again).

The Eagles want to move Mathis. He's been on the trade block.

But no one has so far made a move for a player that hasn't been able to reach his 2012 heights the past two seasons but would cost $4.5 million on the salary cap under his current contract. And, of course, trading for him means trading for his contract as well.

So the Dolphins, and everyone else, have passed so far.

Instead the Dolphins campaigned (hard) during the NFL owners meetings that Dallas Thomas and Billy Turner are penciled in as their starting guards for now.

Please, Lord Jesus, not Dallas Thomas.

Anyway, the Eagles may continue to try to trade Mathis. Or they may eventually relent and cut him, thus saving $4.5 million against their cap this season.

A free agent Evan Mathis might have value for the Dolphins that a trade for Mathis so far has not. Keep that in mind.