NFL free agency has been in full swing for more a week now, and there’s scarcely a sign of Tiki Barber.

With the likes of Nnamdi Asomugha and Kevin Kolb settling into their new high profile positions, teams are moving on to looking for deals, steals, and depth. 

When, and where, will Barber’s name come up?

It’s not as though Ronde’s twin is the only comeback kid this year. His former teammate Plaxico Burress, he of accidentally self-inflicted gunshot wound fame, was a relatively hot commodity in free agency who quickly landed a solid deal with the Jets. Clearly, some franchises are willing to overlook personal transgressions.

Furthermore, the pool of running backs isn’t exactly plentiful (Brian Westbrook is one of the "hottest" names still on the table). 

So why don’t teams seem eager to take a chance on Tiki?

It’s not as though successful un-retirement has never been done before. 

Michael Jordan un-retired after two years and won three straight NBA championships. 

Martina Navritilova un-retired after a decade and made it past the first round at Wimbledon, making her the oldest pro player ever to win a singles’ match. 

Roger Clemens un-retired and won the Cy Young (albeit without missing a season, and likely with an asterisk). 

Still, this is different.

Deion Sanders came closest to a successful NFL comeback. After three years off the gridiron, he signed with Baltimore and played for two mediocre seasons. He didn’t choke, but he wasn’t the old “Neon Deion,” and the Ravens missed the playoffs both years.

In this sport, your 30th birthday puts you over the hill. This sport brutalizes players’ bodies more, some believe, than any other. 

And this is the man who’s been branded a quitter, an adulterer, a traitor and a failure. 

“He turned his back on the Giants family,” lifelong fan Eric Vroman said. “It’ll be a long road to retribution for Tiki.”

And before retribution, it's shaping up to be very long road back to the NFL.

The latest Barber rumor is a Thursday workout with the Miami Dolphins--but the Dolphins already spent nearly $10 million (over two years) signing high profile back Reggie Bush last week, and Miami GM Jeff Ireland is said to be scrambling to clear cap space for ‘Phins’ vets Vernon Carey and Paul Soliai. It’s hard to envision Miami (or other teams, like Pittsburgh, who have been rumored to express interest in Barber) spending any reasonable amount of dough on a high-risk returnee who, in all likelihood, is past his prime.

Barber, for one, seems to understand that teams aren’t exactly going to be jumping into the ring to duke it out for him.

“The game never needs you,” he told HBO Real Sports in an interview last month. “But right now I need the game.”

Though Barber was at the peak of career success (in both ’05 and ’06--his last two years on the field--Barber rushed for more than 1,600 total yards, more than 100 yards per game, and averaged over five yards per carry) when he said his goodbyes four years ago, it seemed the game didn’t even need him then.

The Giants won the Super Bowl the very next season. 

Barber’s critics (a group that had multiplied exponentially in the months leading up the championship, when Barber derided former teammate Eli Manning’s leadership abilities) claimed instant vindication. 

And this spring, when Barber announced his intention to un-retire, football’s talking heads wasted no time in expressing their doubt as to whether Barber can successfully return to the league.

“I didn’t think much of him when he did play,” Warren Sapp said (according to CBS Sports). “He was a fumbler all the way through his life.”

In fact, Barber improved his ball control toward the end of his career, fumbling just four times combined in his last two seasons. Those stats, along with the 1,860 yards he put up in 2005 and the 1,662 he posted in his final year, surpass what last year’s leading rusher, Arian Foster, was able to accomplish.

But Barber is admittedly out of shape after his four-year hiatus. 

This year, with shortened camps and eliminated OTA’s, teams simply don’t have the time to invest in a player who might be a liability. 

Though a source told Fox Sports Barber “looked good” at his Dolphins’ workout, the onetime Pro Bowl-er will need a lot of luck to be signed for any reason other than added depth and injury insurance. 

And to remotely resemble the player he was when he walked away from it all, he just might need miracle.

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