Broncos franchise tag options for 2015 include Demaryius Thomas, Julius Thomas

The 2015 NFL franchise tag period has opened today, February 16th, meaning the Denver Broncos could choose to preserve one of their cherished free agents with a simple one-year guaranteed deal any time now. Here's everything you need to know.

What's the franchise tag?

A franchise tag is a tool a team can use on exactly one player each year to prevent him from hitting free agency. A franchise tag guarantees a player at least the average of the top five contracts at his position, and it's still possible the player will hold out instead of signing it (a situation the Broncos almost faced when they used the franchise tag on Ryan Clady in 2013). The tag also limits Denver's period of time to negotiate a long-term contract with the player; once that period passes, the Broncos and the player are locked in until he hits free agency.

You can read more about the franchise tag an its related tags (transition etc.) here.

When can a franchise tag be used?

The period for teams to use the franchise tag in 2015 runs from February 16th through March 2nd.

How much does it cost?

It's based on position. In 2015:

Quarterbacks: $18.51 million
Running backs: $10.93 million
Wide receivers: $12.80 million
Tight ends: $8.33 million
Offensive linemen: $12.93 million
Defensive tackle: $11.17 million
Defensive ends: $14.78 million
Linebackers: $13.17 million
Cornerbacks: $13.05 million
Safeties: $9.60 million
Kickers/Punters: $4.12 million

Which Broncos could be tagged?

There are four players that come to mind as impending free agents who are potentially worth a franchise tag. Technically, any 2015 unrestricted free agent is a candidate for the tag, but these are the more realistic options, in order of my perceived likelihood of getting tagged.

WR Demaryius Thomas

There are reports that the Broncos are planning on tagging D.T. if they can't get a deal done. This is clearly the most likely choice. Cost: $12.8 million.

TE Julius Thomas

While Julius Thomas' stock fell a bit in Broncos' fans eyes after his injury-riddled end to the 2014 season, he's still without a doubt the most talented tight end about to hit the market. And his price point is considerably less than Demaryius' - perhaps the Broncos can work out a long-term deal with the other Thomas and use the franchise tag on Julius to keep the Thomases intact. Cost: $8.33 million.

OL Orlando Franklin

Orlando Franklin is a left guard and a right tackle in his career, so the challenge with franchise-tagging him is all financial. Offensive linemen are all considered one position as far as franchise tags go, but they are still paid vastly differently, with left tackles making the bulk of the money. This makes it unlikely, although not impossible, that the Broncos would tag Franklin, who would be the most expensive potential franchise tag of the bunch. Cost: $12.93 million.

DT Terrance Knighton

Pot Roast could be a critical piece to the Broncos' switch to the 3-4, but it looks like he and the Raiders might have googly eyes for one another. A franchise tag wouldn't make sense based on is 2014 production (or $2-3 million pricetag), where he played roughly 2/3 less than half of the snaps, but assuming he owns the nose tackle position in Wade Phillips' defense, the franchise tag is a logical possibility. Except for that steep price though. A team could sign Knighton for two years at that rate. Cost: $11.17 million.

Can the Broncos keep all four players?

That was a question posed to me by Football Outsiders' Scott Kacsmar.

Has anyone crunched the numbers to see if Denver can keep Demaryius, Knighton, Franklin and Julius? @MileHighReport

— Scott Kacsmar (@FO_ScottKacsmar) February 16, 2015

Before I take a stab at it (using OTC's salary cap calculator), does anyone in the comments want to give it a try and share their success/failure? I know there are some capologists at MHR who are much more adept at football financials than me.

Who would you tag?

On whom would you use the franchise tag, if you couldn't come to a reasonable deal? Let us know in the poll and comments.