Since Dr. Bennet Omalu published a paper in 2005 discussing the effects of CTE, Chronic Traumatic Encephalopathy, on NFL players, there has been an increase in early retirements from NFL players who would rather live the rest of their lives with full use of their brain instead of waiting until it is too late.
Several players that have died over the past few years have had their brains tested and each one of them tested positive for CTE. The constant trauma on the brain simply from taking hit after hit can cause the brain to slowly die until their is hardly anything left of a player. Junior Seau, Ken Stabler, Bubba Smith, Andre Waters, Mike Webster, and Frank Gifford are some of the recent NFL deaths associated with CTE.
With the number of players being diagnosed with CTE on the rise, players have become very cautious about the value of their NFL career compared to their life. It has left us shocked as some of the biggest names in the business have called it quits recently.
Here are the 15 Most Shocking Retirements in the NFL.
15 Christian Okoye, RB, KC (1992)
In 1987, the Kansas City Chiefs took a chance on the "Nigerian Nightmare" Christian Okoye, and he quickly became their star running back. For six years, he was their lead back and retired as their all-time leading rusher with 4,897 yards and 40 touchdowns. His hard-nosed running style scared the ever living souls out of defenders with his giant 6'1", 253 pound frame that hit like a tank, bulldozing the opposition in the process. He made it look easy but battled knee injuries throughout his entire career which ended up causing him to retire with a few years left of football still in his soul.
He was only 31 years old when he hung it up after claiming that the game was no longer fun. He started seeing the game has a job and once he lost his passion for football, it was no longer something he wanted to risk his body for anymore. He retired and has now become one of the most successful post-NFL career athletes of all-time.
14 Tiki Barber, RB, NYG (2007)
In 2000, Tiki Barber rushed for 1,006 yards, marking the first time he surpassed 1,000 yards in a single season for his career. Two years later, he surpassed that mark again when he rushed for 1,387 yards. That was the first of five consecutive seasons where Tiki Barber rushed for more than 1,200 yards. Between 2002 and 2006, Tiki rushed for 7,643 yards, which was second most in the NFL during that span behind only LaDainian Tomlinson.
So it was a bit of a surprise when Tiki Barber made his intentions known that he was ready to retire following the 2006 season, at the peak of his career because he wanted to protect his future.
In an ironic twist, one of Tiki's biggest career goals was to win a Super Bowl and the Giants seemed destined to be nothing more than a talented team that could not win a Super Bowl. However, the year after he retired, the Giants would defeat the New England Patriots to win Super Bowl XLII.
13 Troy Aikman, QB, DAL (2001)
If he had better protection, and maybe a little bit of luck, then Troy Aikman could have played another six more years in the NFL. But because of a history of concussions, and a nagging back injury that he had been dealing with since 1991, it was finally time for Troy Aikman to hang up the cleats and retire following the 2000 season. He was only 34 years old when he retired, so most fans were shocked to say the least. They were hoping he could play another few seasons at least.
His retirement caused an implosion on the Dallas Cowboys offense that has seen them struggle almost every year since. This season marks one of the first times since the 90's Cowboys dynasty that the fans in Dallas have an actual feeling of hope for another Super Bowl title.
12 Jerod Mayo, LB, NWE (2016)
After three consecutive seasons ending early due to injury, Jerod Mayo decided it was time to move on and he officially retired from the NFL on February 16, 2016. It was an unfortunate ending to a once promising career with the New England Patriots, where he played all eight seasons of his NFL career.
In the first five years, he was mostly healthy and played in 75 games, starting 73 of them including all 16 during his 2008 rookie season. He wound up with 126 tackles that year and was already becoming a team leader, right out of the gate. In 2010, he would have his best season of his career with 175 total tackles, two sacks, three fumble recoveries, and he was credited with five pass deflections. He was a part of the Super Bowl XLIX winning team and did earn himself a ring before he decided to retire from the game.
11 Gale Sayers, RB, CHI (1972)
Gale Sayers was one of the NFL's greatest running backs of all time that we will never quite know just what he could have become had his knees held up. Unfortunately for him, he battled several knee injuries and had gone back and forth with retirement and trying to play but he could not get away from those nagging injuries that just kept slowing him down.
At 29 years of age, he officially retired following his second comeback in which he played in a 1972 preseason game for the Chicago Bears and fumbled twice. He was not the same and knew right then that he had to give it up because he had nothing left in his tank. His legacy remained intact and he was inducted into the Pro Football Hall of Fame in 1977 after just 68 games over seven seasons. He is tied for fourth on the list of Pro Football Hall of Famers with the fewest games played.
10 Bo Jackson, RB, OAK (1991)
There has never been a better athlete in professional sports since Bo Jackson. In fact, there have not been many, if any, two-sport athletes like Bo Jackson since the '90s. But not a single one of the two sport athletes in professional sports history could come close to Bo Jackson's talent. He was simply a freak on the football field and a monster on the baseball diamond. He ran like Adrian Peterson, but faster, and he threw the baseball like Willie Mays, only faster. He hit like David Ortiz, but was smarter when running the bases, oh, and he was faster.
But his powerful running style made him a candidate for the injury bug and during a 1991 playoff game against the Cincinnati Bengals, he dislocated his hip after a tackle. It would be his final play in the NFL leaving fans always wondering what could have been if he was able to just stay healthy.
9 Robert Smith, RB, MIN (2001)
When Robert Smith left the NFL, he was another one of the surprises because he was not only healthy, he was actually one of the biggest free agent running backs on the market heading into the 2001 season. He could have signed for nearly $30 million dollars but decided to give it all up because he was afraid of his future health.
He retired right around the time many other athletes started leaving the NFL after being practically forced out because of brain injuries, mostly concussions. It was before the infamous CTE discovery but Robert Smith could see it happening long before anyone else did.
8 Tony Boselli, LT, JAX (2002)
Tony Boselli is the only player in NFL history to be drafted twice by two different franchise's, as their top pick. When the NFL added the Jacksonville Jaguars, they were one of two expansion teams in 1995. The Carolina Panthers were the second team and both of them participated in the 1995 NFL Draft as the top two picks. After adding 31 players to their franchise, Jacksonville entered the draft looking at several key players they were going to need if they wanted to find success. So they drafted Tony Boselli with the second overall pick. He was later drafted by the Houston Texans as their first ever selection, during their expansion draft.
However, due to injury, Tony would not be able to play for Houston and ended up retiring shortly after he signed on with the team later on in the year at the age of 29, which is very young considering most offensive lineman go well beyond that in terms of years in the NFL. He only played seven seasons, making five Pro Bowls and three All-Pro teams.
7 Patrick Willis, LB, SF (2015)
The San Francisco 49ers have dealt with their fair share of problems since the Joe Montana-Steve Young era ended in the late '90s. There was a few years of success with Jeff Garcia behind center, along with Terrell Owens, but once that duo stopped working well together, the team fell apart and struggled for several years before they hired Jim Harbaugh and immediately found success from the defensive side of the ball.
Patrick Willis was a huge part of that turnaround for the 49ers and was their leading tackler, as well as the NFL's top tackler for the first four seasons in the league. He was a monster on the field and could cover just about anyone that was thrown his way. But he started battling a foot injury in 2013 that carried over through 2014 and eventually made him have to make the tough choice of playing in the NFL and risking further injury, or retiring. He chose the later and shocked everyone, especially 49er fans.
6 Chris Borland, LB, (2015)
Just around the same time Patrick Willis made his announcement, so did the rookie Chris Borland, which could be considered the most shocking retirement in franchise history as he only played one year. He barely even had time to get his feet wet, starting only eight games for the 49ers, after Patrick Willis went down with a foot injury.
Chris found success as the team's starting inside linebacker and finished his rookie year with 107 tackles, two interceptions, and a sack. It was quite the start for the rookie from Wisconsin but his season wound up coming to an end when he was sent to the injured reserve after a season ending ankle injury.
He stated that he was retiring because of concerns with head trauma.
5 Marshawn Lynch, RB, SEA (2016)
In an off-season where NFL fans were sitting around waiting to hear Peyton Manning announce the very predictable news about his retirement, several other players stepped in and shocked us with their own retirement announcements. Marshawn Lynch, the Super Bowl champion Seattle Seahawks running back, made an unexpected decision last year when he decided to walk away from the game at the age of 29.
He had much left to give but still retired as one of the league's best running backs having rushed for 1,000 yards in a single season six different times. He was a consistent star running back in Seattle having rushed for 6,347 yards during his time with the Seahawks. In all, he rushed for nearly 10,000 yards and had 74 rushing touchdowns making him a star running back in only 10 years in the NFL.
4 Jim Brown, RB, CLE (1966)
Jim Brown was one of the most talented all-around athletes ever to play in the NFL. He was faster, stronger, quicker, and better than the rest of the league, while he was playing, so when he retired after just nine seasons, it came as a surprise to everyone that was a fan of the big fullback from St. Simons Island, Georgia.
But he had other plans and after he accomplished all he felt he could in the NFL, he decided to continue down another career path, in acting. So he left the league and started showing up in Hollywood as a healthy, former NFL player with all of his teeth and no long term concussion injuries that could have caused him to follow in the footsteps of many of the other former NFL superstars from several decades ago.
3 Calvin Johnson, WR, DET (2016)
The Detroit Lions have been among the worst NFL franchises for several years now and have spent a lot of time losing in the process. They have become used to losing and have a revolving door of head coaches, none of which have been able to turn things around in Michigan.
As a result of their consistency in the loser's column, Calvin Johnson decided to retire following the ending of the 2015 NFL season, a move that shocked just about everyone.
When asked about his decision to retire, Calvin Johnson said, "I don't know, but what I can tell you, is that it's a big unknown because... say you were winning, you win a Super Bowl and you know, you just never know how you'll feel. I'm wasting my time trying to think about what could happen, what would have been..."
2 D'Brickashaw Ferguson, OT, NYJ (2016)
As far as shocking goes, this one is probably the most off-the-wall retirement announcement that no one saw coming because of so many factors. For one, D'Brickashaw Ferguson was healthy. He was the healthiest he had ever been in his career when he made the call. Also, he is a Pro Bowl offensive lineman that was still at the top of his game and was ranked among the leagues top Left Tackles heading into this past season.
In ten seasons in the NFL, Ferguson played in every single game, 167 consecutive starts, and not a single missed practice or even a mention on the injury report. He was truly as reliable as they come. But his growing concern over the NFL's concussion problem caused him to make a choice that would protect his future outside of football.
1 Barry Sanders, RB, DET (1999)
Of all the players on this list, there is not a single one that was more shocking than Barry Sanders. He announced it in the middle of the summer, just as training camps were getting started and players were beginning to report for the upcoming 1999 season.
It was a shock because just a few years prior to his retirement, he renewed his contract with Detroit for $35.4 million, with an $11 million signing bonus, for a total of six more years. During the next off-season, the Lions started to demand that he return half of the signing bonus, $5.5 million, but Sanders refused to do so unless the Lions would release him and allow him to sign wherever he wanted to. Detroit decided not to grant him a release or even trade him per his request and that stand-off turned into Barry Sanders never returning to the NFL.
If they could have only allowed him freedom to sign somewhere else, then who knows what could have happened. He definitely would have broken the NFL's all-time rushing record.