Athletes—particularly NFL athletes—don't always know when to call it quits.
Be it age or nagging injuries, most of them don't know anything else other than the sport they've played all their lives.
In our modern age we're living well into our 80s and 90s, and people in their 30s are still considered young.
However, in the NFL you're considered old once you've reached 30 and ancient if you make to 35 and are still on an active roster.
This list consists of 11 2011 free agents who may just hang it all up within the next two years.
Some will do it because they recognize their age and that their ability has slipped, so instead of being a shadow of their once-great selves they'll bow out.
Others will hang around too long and will only decide to call it quits because they'll feel disrespected by the lack of money they are offered.
And we have one more group, one that regardless of age, diminished talent, or lack of big contracts will hang around too long and their career might end on a stretcher.
Brett Favre will go down as one of the greatest quarterbacks to have ever played the game.
Right before his last season in Green Bay it had looked as if the "old man" had stuck around a season too long, but then the Packers went on the miraculous run to the NFC Championship game and were quite close to going to the Super Bowl.
At the end of the game a tearful Favre said he was done. He made it official later in the offseason and retired.
The Packers had been ready for this for a few seasons and had a former first-round pick in Aaron Rodgers waiting in the wings.
The starting job was given to Rodgers, then Favre un-retired and ESPN's wet dream of a news story was born.
From there we saw Favre traded to the Jets, where he proved he had gas left in the tank, but once again retired, to then—of course—un-retire and join the Vikings.
Once again Favre proved that even at his advanced NFL age he was still one of the best, and eerily like his last season in Green Bay it ended in a loss in the NFC Championship game.
In the 2009 offseason we didn't get the Favre drama because he was determined to come back in 2010.
Well 2010 was disastrous for Favre. The Vikings were plagued with injuries and were just terrible. Favre was accused of sending x-rated pictures to a female P.R. rep for the Jets, and he saw his consecutive game streak come to an end.
The Vikings are ready to move on without him, but it seems like Favre still wants to comeback.
Luckily for us the "will he or won't he?" reports have been overshadowed by the NFL lockout (of course, the unlucky thing here is that there is a lockout).
However, there is no official word that Favre is retired.
I honestly think he'll be back in 2011, and I honestly think he'll be done within the next two seasons. Not by his choosing, unfortunately.
Sadly, Favre may end up as one of those players who stuck around too long and the last we see of him on an NFL field just might be him being carted off.
Matt Hasselbeck will be 36 this season, and just judging by his last two years his play has dropped significantly.
After following Mike Holmgren to Seattle from Green Bay, Hasselbeck proved to be one of Holmgren's best-kept secrets.
Though not as good as the man he was drafted to back up, Hasselbeck proved to be Brett Favre's equal every once and a while.
However, it seems that Seattle (with no actual plan at QB) is ready to move on without Hasselbeck and his best bet for a job right now is either as a back-up or to groom one of the many rookie QBs coming into the league.
It's really hard to say how much Hasselbeck has left in him. If he takes the back-up route he could have maybe three to four years left, but if he goes to Tennessee or Carolina to mentor a rookie his number could be up before the season is over.
Todd Collins—who turns 40 this year—was drafted in the way-back year of 1995 as a back-up for Bills' super quarterback Jim Kelly.
Jim Kelly Todd Collins is not, but he did have one magical season in Washington in 2007 when a late-season injury to Jason Campbell seemed to doom the Redskins' dwindling playoff hopes. Following the death of safety Sean Taylor and a loss to the Buffalo Bills, all the wind seemed out of the 5-7 Redskins' sails.
Collins, though, lead a charge and helped the Skins win five straight and marched them into the playoffs.
There was no controversy in DC, however, when the next season rolled around Campbell was still the starter and after the 2009 season Collins was released.
He signed a one-year deal with the Bears in 2010 and the few times he saw the field it was very lack-luster.
However, Collins has not announced or hinted at any plans to retire this offseason, so expect him somewhere in 2011.
No matter where he ends up I'm sure it will only be a one-year deal, and even if he stays on a roster through 2011 and wants to play in 2012 eventually the phone will stop ringing for his back-up services.
Clinton Portis has been a workhorse for the Redskins over the past six seasons and he's lasted a lot longer than many who have played his position and have taken the pounding he has.
Sadly, the normally durable Portis has ended his last two seasons on injured reserve, and with injuries continuing to mount one has to wonder if he's even got anything left in the tank.
He'll be back somewhere in 2011, probably on a one-year league-minimum contract and probably in a limited third-down role.
Portis is one of those players who feels he has a lot left to prove on the field and unfortunately will probably fall under the category of players who stayed too long and were carried off the field instead of walking off on their own terms.
Ricky Williams once retired from the NFL in 2004, though his ability to play wasn't the reason.
He came back in 2007, so the 34-year-old's legs are as old as other 34-year-olds in the NFL.
However, he's still 34 and his age is going to catch up with him no matter how long he took off. In fact, it's rare these days to see a running back older than 30 in the NFL (well, outside of New England, that is).
The last season and a half has seen Williams' game go downhill a bit, and if he was disinterested and wanted to retire a decade ago while he was in his prime I doubt he'll stay around too much longer.
Faulk has been a starter/back-up running back in New England for his entire NFL career.
However, the 35-year-old has been injury-prone, and even though he's spent most of his career sharing carries he really began to show his age last season.
He wants to return to the Pats this year but we all know how Bill Belichick feels about aging free agents.
I wouldn't be too surprise if the Pats passed on Faulk and he decided to hang them up this season; but if he does play one more year I'll be shocked to see him lacing up in 2012.
The 35-year-old Fred Taylor was drafted in 1998 by the Jacksonville Jaguars, and for a decade he was the most recognizable face on the team.
However, there was a younger and faster back on the roster by the name of Maurice Jones-Drew and Taylor was released by the Jags after the '08 season.
He was picked up by the New England Patriots and teamed with Kevin Faulk. The two aging backs split carries to lighten their loads but at 35 Taylor's legs aren't what they used to be.
Randy Moss (34) had a magical mystery tour through the NFL last season.
After being visibly disgruntled in New England, he was traded to Minnesota to be teamed with Brett Favre. Both played poorly and there were reports that Moss was a bit of a locker room disruption and was placed on waivers after only two games.
Moss landed with the Titans, where he quickly faded into the background.
After last season, I highly doubt any team (except maybe Dallas) will offer Moss a contract of any significant value, and Moss being the diva he is might feel disrespected by such a low offer could just up and retire this season.
Either way, any offer Moss gets will likely be for one year and incentive-laden, and judging by his 2011 performance will probably determine if he retires soon.
Terrell Owens will turn 38 this season and just had ACL surgery, but still wants to play in the NFL.
I'm not sure if he'll be able to, though. Owens was on a bad Bengals team last year but still managed to put up good numbers, especially for his age.
However, given his age, his injury and his attitude, I don't know of too many teams that would be willing to sign him.
This might be a case where Owens either takes a year off or retires because the phone isn't ringing.
Santana Moss at the age of 32 is relatively young compared to some of the players on this list, but given his size and the fact that no matter where he lands this offseason (I'm banking on a return to DC) he'll be relegated to the slot.
With the number of passes he'll catch over the middle as well the pounding he's going to be taking, I honestly don't see how Moss will be able to last much longer in the NFL.
Pat Williams will turn 39 this season and with his 6'3", 317-pound frame the clock is ticking on the remainder of his career.
Williams played well last season and this extended break due to the lockout could work in the defensive tackle's favor.
But even if he only plays part time he can't possibly keep up an NFL pace much longer.