It's no great surprise to anyone, everybody who grows a year older feels the creaks and pains of yet another 365 days of wear and tear.
It's no different with NFL players. Although we want our favorite players to keep up the same high-level play, Father Time has different plans for all of us.
There comes a time when everyone has to come to terms with the fact that maybe "they just aren't as young as they used to be." While it's not to say these players should be put out to pasture quite yet, a decline in skills should come as no surprise to anyone for these 10 men.
Ray Lewis going downhill comes as no surprise. He's been absolutely dominating over the last decade, but Baltimore has been drafting to replace him for the last two seasons.
Sergio Kindle should see a lot of reps come the end of the season, and with any luck, he may be leading the Ravens for years to come.
Ray Lewis is the ripe age of 34, and while he may still be punishing running backs at the line of scrimmage, it can't last. The old expression "you're only as old as you feel" may be one that Lewis has taken to heart, but science says it's just a matter of time.
Originally drafted as a Pittsburgh Steeler, Faneca has spent the last few seasons as a fixture of the New York Jets offensive line. D'Brickashaw Ferguson and Nick Mangold were outraged to find out this offseason that Faneca's time in New York had run out.
As one of the most dominating linemen of the last five years, the Jets decided that his play had suffered enough to be able to replace him easily with a rookie in the 2010 draft.
While it remains to be seen if Arizona can rekindle some magic with Faneca, his best days are clearly behind him.
Randy Moss catches passes from arguably the best passer in the NFL, Tom Brady, and put up 1,294 yards last season. What reasoning would anyone have to think that Randy Moss may be on the decline?
The simple fact is Moss will be 33 at the start of the season and he's never shown the best dedication to the sport.
The Patriots have a duo of younger receivers in Taylor Price and Julian Edelman itching to make their names known named, as well as leading receiver Wes Welker. Give it time. Moss will be fazed out slowly.
With 142 tackles, Fletcher was a force on the Washington Redskins last year, but for now it's a race against the clock. Fletcher will be 35 in two weeks, and the human body can only take so much abuse.
One of the most durable and consistent linebackers in the NFL may be in for hard times in the next few seasons, as injuries and age will start to rear their heads soon enough.
Going from Ferguson, Mangold, and Faneca to the Kansas City Chiefs' offensive line is hard times for anyone. Let alone for a running back who will be 32 at the start of the season.
Even with the emergence of Shonn Greene in New York, it came as a surprise that New York would let go of a back who ran for 1,402 yards last year, drafting USC's Joe McKnight to replace him.
It happens to all backs over 30, the great running back decline.
Asante is a ball-hawking cornerback that has put up great numbers for the last seven seasons, but for such a hard hitting player to continue playing at such a fast-paced level isn't practical.
Concussions are frequent and injuries are a matter of time. While Samuel is only 29, the secondary is an accident-prone position, and the kind of impacts Asante lays out make for a rough season.
It seems like McNabb just keeps getting better and better lately. The problem being is his offensive line has just taken a shot moving from Philly to DC, and McNabb didn't have much room to work with in the first place.
The injuries have piled up year after year, and with a significantly weaker line this season, the 34-year-old McNabb may not be able to be the savior Dan Snyder thinks he will be.
It seems like the age of 30 on offense in the NFL is like playing the death card, for Steve Smith who has relied so much on quickness to get open, it may be a rude awakening for him soon. With mounting injuries and inconsistent quarterback play, he failed to even break 1,000 yards last year.
With a combination of Matt Moore, Jimmy Clausen, and Tony Pike this year, will Smith rebound? History points to no, but he's a tremendous talent and if anyone can come back, it's Steve Smith.
Ochocinco's numbers have progressively gone down each season as of late. Whether it's due to injuries or a regressive streak of play from Carson Palmer, the point remains.
Ochocinco is 32 years old and has clearly lost a step. He'll be in for a tough sell when his contract with the Bengals is up.
In 12 seasons Peyton Manning has not missed a single game. The definition of tough, Manning always plays through the pain and carries the Colts on his back.
The big question is, how much longer can he continue to do it before that back gives out?
Peyton is 34 years old and has been taking an increasing amount of hits lately. While he may be the best quarterback of all time, arguably enough, the numbers and productivity simply can't hold up.
How soon before Indy needs to start thinking of reliable backups?