AP

From 21 in 2012 to eight in 2013 to only four in 2014, the franchise tag has quickly fallen out of fashion in pro football.

For 2015, the two-week window for applying the franchise tag opens Monday. So let’s take a team-by-team look at the potential recipients of a designation that has been drying up in recent years.

Arizona Cardinals: Cornerback Antonio Cromartie is due to hit the market, but the Cardinals already have plenty invested in the position, thanks to the Patrick Peterson contract. Cromartie was solid last year for the Cardinals, but not franchise-tag solid.

Atlanta Falcons: The closest guy the Falcons have to being worthy of franchise-tag consideration is kicker Matt Bryant. Linebacker Sean Weatherspoon’s injury-related absence hurt the team badly in 2014, but it would be ludicrous to tag a guy coming off a torn Achilles tendon.

Baltimore Ravens: Despite plenty of promise early in his career, receiver Torrey Smith hasn’t developed into a complete receiver. His sub-900-yard contract year won’t get him tagged, and it may not get him a huge offer on the open market. Running back Justin Forsett had a surprisingly strong season, but he’ll be 30 in October and he plays a position that rarely makes anyone rich. The far more likely tag recipient is defensive end Pernell McPhee, but with Haloti Ngata and Terrell Suggs that could be too much of a cap commitment.

Buffalo Bills: Defensive end Jerry Hughes, with a pair of 10-sack seasons, becomes the most obvious choice for application of the tag in Buffalo. But with $19.4 million in cap space already devoted to defensive end Mario Williams, sinking at least $13 million into the same position likely becomes more than the Bills can justify — especially with a defensive-minded head coach who can generate pressure on quarterbacks without devoting more than $30 million in cap space to a pair of pass rushers.

Carolina Panthers: It would cost $15.72 million to tag defensive end Greg Hardy again. After paying him $13.1 million for only one appearance in 2014, the Panthers likely will pass. They’ll also likely pass on everyone else on the roster who is due to become a free agent.

Chicago Bears: With plenty of tough decisions to make this offseason, using the franchise tag isn’t one of them.

Cincinnati Bengals: Tagged in 2012, kicker Mike Nugent’s contract is up again. But even though the franchise tender for specialists is a lot lower than the tender for other positions, more than $3.5 million is a lot to invest in a player who plays a position that is largely interchangeable. Tight end Jermaine Gresham has name recognition, but with Tyler Eifert in the fold and plenty of other skill-position players to pay in the coming years, the Bengals wouldn’t invest more than $7 million for another year with Greshman.

Cleveland Browns: Quarterback Brian Hoyer may be back, but definitely not at the quarterback franchise tender. The more intriguing option is tight end Jordan Cameron. He reportedly wants out of Cleveland, but with few other strong options in the passing game, the Browns may decide to use the franchise tag to keep him in place. Or they possibly will apply the transition tag, which they used in 2014 to retain center Alex Mack, who signed an offer sheet with the Jaguars, and the Browns quickly matched. Cornerback Buster Skrine is a longshot, given the money invested in Joe Haden and the draft pick invested in Justin Gilbert.

Dallas Cowboys: With a pair of big-name offensive weapons poised to hit the market, the popular belief is that one or the other will be tagged. Chances are receiver Dez Bryant finds himself getting paid more than $12 million for one more year with the team under the franchise, barring an unexpected off-field issue that makes Dallas unwilling to mimic the Panthers. Running back DeMarco Murray also is a candidate for the tag, but a long-term deal would be far cheaper for Murray than it would be for Dez.

Denver Broncos: The most obvious candidate for the tag is receiver Demaryius Thomas. Tight end Julius Thomas could get consideration, if Demaryius Thomas signs a long-term deal. Defensive tackle Terence Knighton also could be a possibility, if both Thomases are signed — or if Demaryius gets a new contract and the Broncos decide to let Julius Thomas hit the market.

Detroit Lions: Tagging defensive tackle Ndamukong Suh would cost $26.8 million, based on his cap number in 2014. While G.M. Martin Mayhew hasn’t ruled it out, tagging Suh would make it difficult for the Lions to do business with that much cap space tied up in one player — especially since another $36 million is earmarked for quarterback Matthew Stafford and receiver Calvin Johnson.

Green Bay Packers: Receiver Randall Cobb heads to the market, and the Packers likely won’t stop him with the franchise tag. With a major commitment made to Jordy Nelson and high hopes for Davante Adams, there’s no reason to invest that much money in a position that benefits greatly from the presence of quarterback Aaron Rodgers. Tackle Bryan Bulaga has become a solid option on the right side, but the tag ends up reflecting the top of the left-side market, since all positions on the offensive line fall into one general bucket.

Houston Texans: The biggest name from their coming free agents belongs to cornerback Kareem Jackson. His name and performance isn’t big enough to merit an eight-figure salary for one year.

Indianapolis Colts: With the strength of this team in its youth, there simply aren’t any veterans with expiring contracts worth consideration of the tag.

Jacksonville Jaguars: They’d probably like to bring back receiver Cecil Shorts, but not at the franchise tender. That’s really the only benefit of having a perennially mediocre team; no players are good enough to force application of the tag.

Kansas City Chiefs: The Chiefs won’t be allowing linebacker Justin Houston and his 22.0 sacks to walk away; absent a long-term deal, he gets the tag.

Miami Dolphins: Tight end Charles Clay has become a solid performer for the Dolphins, but $7 million for another year is a lot to pay for 58 catches, 605 yards, and three touchdowns. It would be a surprise if the Dolphins tag Clay. Ditto for defensive lineman Jared Odrick; the Dolphins have a ton of cash already tied up in the front four.

Minnesota Vikings: The Vikings have no free agents who’d be worthy of the tag.

New England Patriots: Safety Devin McCourty’s name has been linked most often with the tag. Kicker Stephen Gostkowski is another option, and his tag number would be a lot cheaper. Using it on either guy (especially on McCourty) would give cornerback Darrelle Revis even more leverage as the Patriots face trying to carve down a cap number that becomes $25 million for 2015 if he’s on the roster as of March 10.

New Orleans Saints: The cap-strapped Saints won’t be whipping out the tag; no one from their class of emerging free agents deserves even a discussion about the use of it.

New York Giants: The Giants haven’t ruled out tagging defensive end Jason Pierre-Paul, but it would be risky. Between a stellar 2011 and a great 2014, JPP had mediocre performances in 2012 and 2013, due in large part to back problems. Since a season with the tag would operate as a second straight contract year, maybe the Giants would get even more out of Pierre-Paul in 2014 than they saw in the final season of his rookie deal.

New York Jets: Several years ago, linebacker David Harris was considered to be one of the key long-term components of the team’s defense. Now 31, the sense of urgency to keep Harris in green and white doesn’t seem to be as strong as it used to be. It’s hard to imagine the Jets making a one-year, eight-figure investment in an aging inside linebacker, even if he has started every game since the 2009 season.

Oakland Raiders: One of the worst franchises in the NFL has no viable candidates for the franchise tag.

Philadelphia Eagles: Last March, receiver Jeremy Maclin opted for a one-year deal after having his contract year wiped out by a torn ACL. The Eagles now must decide whether to extend his stay with another one-year deal that will include an investment far bigger than the one they made a year ago. While Maclin doesn’t fit coach Chip Kelly’s big-receiver mold, Maclin became a reliable target in 2014. Whether that makes him reliable enough to justify an eight-figure payday for only one year is something only Kelly will know.

Pittsburgh Steelers: Last year, the Steelers surprisingly applied the transition tag to linebacker Jason Worilds. This year, either the transition or franchise tag would entail a 20-percent raise, driving his salary and cap number north of $13 million. With quarterback Ben Roethlisberger counting more than $18 million under the cap, it’s very unlikely that the Steelers would tag Worilds again.

San Diego Chargers: Cornerback Brandon Flowers landed in San Diego’s lap after being cut by the Chiefs. It’ll now take a lot of cash to keep him around via the franchise tag; that’s probably more extravagant than the Chargers intend to be if they hope to keep Flowers around.

San Francisco 49ers: A few years ago, receiver Michael Crabtree seemed to be heading in the direction of a big-money deal or the franchise tag. Now, he’s heading for neither — and quite possibly for a new team. Guard Mike Iupati is an important piece of the offense, but with left-tackle money determining the tag at all offensive line positions, it makes no sense to devote that much to an interior blocker.

Seattle Seahawks: The Seahawks would like to keep cornerback Byron Maxwell (in part because they’d surely like to keep Tharold Simon off the field). But application of the tag makes little sense for a team that has paid big money to three starters in the secondary, that needs to pay middle linebacker Bobby Wagner and quarterback Russell Wilson, and that is getting hijacked by Marshawn Lynch’s second annual retirement speculation convention.

St. Louis Rams: The Rams have a few free agents they’d be wise to keep (like receiver Kenny Britt) but none that deserve franchise-tag money.

Tampa Bay Buccaneers: Signs are pointing to the Bucs spending a lot in free agency. That money likely won’t be spent via the franchise tag.

Tennessee Titans: Michael Roos is one of the top free-agent tackles, but not good enough to justify the franchise tag. Punter Brett Kern and kicker Ryan Succop merit consideration. Beyond them, none of Tennessee’s looming free agents do.

Washington: Last year, they tagged Brian Orakpo — and they eventually regretted it. This year, Orakpo hits the market, along with the rest of the team’s looming unrestricted free agents.