Why did so many good NFL free agents settle for 1-year ‘prove it’ deals?

Dontari Poe’s career has been predicated on proving he has what it takes to be an impact defensive lineman. As a two-star prospect, he had to prove he belonged as an FBS football player. After an underwhelming college career at the University of Memphis, he had to prove he had the talent and drive to make an NFL roster. After blowing scouts away with an impressive combine performance, he had to prove to the Kansas City Chiefs he was worthy of their first-round pick.

But now, five years into a successful NFL career that’s featured two Pro Bowl selections and one All-Pro honor, he’s being asked to prove himself once more.

Poe couldn’t find a long-term contract to his liking on the 2017 free agent market, instead settling on a one-year, $8 million deal with the Atlanta Falcons. If he plays up to his own high expectations, then he’ll have the chance to capitalize on a banner contract year and parlay that into a longer contract.

Poe isn’t alone when it comes to signing a “prove-it” deal in 2017. This offseason has seen several blossoming, young players ink one-year deals after teams got stingy about handing out multi-year pacts. Poe’s replacement in Kansas City, former Eagle Bennie Logan, followed up his rookie contract with a one-year, $8 million deal. Alshon Jeffery, who had been given the Bears’ franchise tag in 2016, signed with the Eagles for one year and $9.5 million.

Here’s a partial list of the notable names to sign single-year tenders.

Through the first 11 days of free agency, 36 players aged 28 or younger had been signed to one-year deals. Excluding fliers — deals for less than $1 million on lower-profile players, let’s say — that means these talented young athletes and their short-term deals made up more than 32 percent of the early market for players in that age group so far.

Last year, of the 91 deals worth at least seven figures annually and given to players aged 28 and under, 28 — or 30.7 percent — were single-year deals. In 2015, 21 of 69 deals for players in that age group — 30.4 percent— fell into the same category.

While an increase of less than 2 percent may not seem like much now, it’s notable this shift is happening so early in the offseason. Many one-year deals are struck towards the end of the period as players and agents run out of options. That 2017 number is primed to grow rather than fade.

Some cases make more sense than others. Jeffery is a Pro Bowl talent who played only 21 games the past two seasons thanks to a combination of injuries and a league-mandated suspension. Terrelle Pryor had a breakout year as the Browns’ top wide receiver, but 2016 marked only his first full season at the position.

Morris Claiborne signed a one-year “prove-it” contract with the Cowboys in 2016 and played some of the best football of his career — but lasted only seven games last fall due to a groin injury. Former first-round picks like Datone Jones, D.J. Fluker, D.J. Hayden, Jarvis Jones, Kendall Wright, and Barkevious Mingo never lived up to the hype that came with their lofty draft statuses.

Others, like Poe’s deal, are more curious. Despite a rising salary cap, league owners appear to have more leverage over young players coming off their rookie contracts in 2017.

The driving force could be a rising tide of defensive talent set to hit the league in this April’s NFL draft. SB Nation analyst Dan Kadar currently has 17 defenders earning selections in his top 32, which leaves out solid prospects like Alabama’s Ryan Anderson and UCLA’s Takkarist McKinley along the way. The cost of adding defensive tackle Kenny Clark with the No. 27 pick last year was a four-year, $9.38 million contract for the Packers — or just $1.38 million more than what it would cost to rent Poe or Logan for a single season.

That increased supply doesn’t just apply to linemen. The emergence of college backs like Leonard Fournette, Dalvin Cook, Christian McCaffrey, and Alvin Kamara made taking a long-term risk on Eddie Lacy — who also signed a one-year deal with the Seahawks — an irrational decision. A draft where as many as eight defensive backs could be selected on opening night softened the market for once-touted players like Prince Amukamura and Claiborne.

With low-cost replacements eager to make their NFL debuts, young veterans are getting squeezed into short-term deals set to gauge their staying power in the league. Some big names will have 16 games to prove their worth and chase a big-money long-term contract in 2017. If they can’t live up to their billing, it could mean leaving millions of dollars on the table.