The greatest players to ever grace the National Football League are names that are known in North America and also among sports fans located overseas. Jim Brown, Lawrence Taylor, Tom Brady, Barry Sanders, Walter Payton, Peyton Manning, and Brett Favre are just some of examples of pro football legends who will live on in the memories of football fans thanks to NFL Films, the NFL Network, television specials produced by ESPN and other media creations. Football stars of the now and the future of the NFL – J.J. Watt, Andrew Luck, Aaron Rodgers and others – are featured in advertising campaigns and even international television commercials.

The men perceived to be among the worst players in NFL history are also remembered by fans and analysts, but for different reasons. It should be pointed out that a lack of talent alone does not make one a terrible NFL player. Former Ultimate Fighting Championship competitor and current World Wrestling Entertainment performer Brock Lesnar could not get past the practice squad of the Minnesota Vikings, but that does not make him one of the worst players in NFL history because nobody should have had any expectations that the amateur and pro wrestler would have been able to make the transition to pro football at the drop of a hat.

The biggest factor for a player to make the list of the worst players in NFL history is that individual being a disappointment for the team that acquired him. Quarterback is the most important position in the game, and thus it should not be a shock that the position is found at the top of this list. Included in those subjects is a man who clearly was not psychologically or emotionally prepared to play in a league followed by millions of fans. The list also includes a man who apparently liked buffet lines more than he enjoyed leading NFL offenses on Sundays. They are two reasons why rookies no longer get blank checks upon entering the NFL.

20 20. John McKay Jr.

John McKay Jr. starts off the list in part because he brazenly shunned the Cleveland Browns in favor of World Football League franchise, the Southern California Sun. He eventually chose to launch his NFL career with the Tampa Bay Buccaneers, a controversial move because his father was serving as the head coach of that team. The perception had by some teammates was that McKay did not belong on the team or in the NFL, and quarterback Steve Spurrier allegedly purposely hung McKay out to dry with passes over the middle on multiple occasions. McKay would reel in a total of 41 passes over three years before a hand injury ended a NFL career that probably shouldn't have ever existed.

19 19. Shante Carver

The Dallas Cowboys were known as the NFL “Team of the 90s.” Shante Carver was not a reason for this. The 23rd overall pick of the 1994 NFL Draft was injured throughout his rookie campaign, and he then earned a six-game suspension in 1996 for repeatedly violating the NFL drug policy. Perhaps the most-telling note of Carver's career is that he accumulated six sacks and started in all 16 regular season games in his final year in Dallas, and yet the Cowboys still let him go. But wait. There's more. No other NFL team bothered with Carver and his NFL career ended after 1997.

18 18. Babe Laufenberg

History has been somewhat harsh on Babe Laufenberg. He was, after all, taken in the sixth round of the 1983 NFL Draft. With that said, Laufenberg was awful during the four years during which he made appearances in the league. Only 93 of the 211 passes attempted by Laufenberg were completed to receivers, and just five of those plays resulted in touchdowns. He did only toss 11 interceptions during his career, but that may have been more so a result of Laufenberg not being able to hit anything more so than it is a testament of his ability to avoid turning the ball over.

17 17. Larry Stegent

Professional athletes get injured. It happens. That reality does not mean, however, that a player was not a waste of a draft pick. The St. Louis Cardinals spent the eighth overall pick of the 1970 NFL Draft on Larry Stegent and here is what the club received for its troubles: Seven total appearances, one start, zero rushing attempts, one reception for a gain of 12 yards, and a bad knee. That's it. That is all that Stegent was able to give to St. Louis during his one season in the NFL. It is almost as if Stegent never played in the NFL in the first place.

16 16. Mike Junkin

And you thought that the Cleveland Browns trying to outsmart the rest of the NFL was a new occurrence. The Browns traded up in the 1987 NFL Draft to take linebacker Mike Junkin out of Duke University with the fifth overall pick, and Junkin proved to be maybe the worst draft pick in the history of the franchise. Junkin started in just seven regular season games for the Browns in two seasons, he failed to make tackles and to learn how to play linebacker in the NFL, and he became an afterthought after the Kansas City Chiefs gave up on him following the 1989 season.

15 15. Bernard Williams

The Philadelphia Eagles spent the 14th overall pick of the 1994 NFL Draft on the offensive tackle, seemingly unaware that Bernard Williams liked to smoke marijuana; a lot. Williams started in 16 games for the Eagles during his rookie year, but he would never again play in the NFL because of his inability to pass drug tests. Williams failed several league drug tests before he was informed that he was no longer allowed to perform in the NFL. Learn from this story as quickly as possible, Cleveland Browns wide receiver Josh Gordon, or be doomed to repeat it.

14 14. Kim McQuilken

It is a good thing that Kim McQuilken proved to have the goods to be an executive vice president at the Cartoon Network, because the guy was a lousy NFL quarterback. McQuilken did, to his credit, manage to hang around the league for a total of five seasons, during which he attempted a total of 272 passes. He completed only 108 of those attempts, a mark good for a completion percentage of 39.7. His resume for being among the worst players in NFL history is bolstered by the fact that McQuilken matched four touchdown passes with 29 interceptions. Yuck.

13 13. Lawrence Phillips

Lawrence Phillips never belonged in the NFL. Ever. Phillips was a despicable human being during his days at the University of Nebraska and it also turned out that he was more so aided by the play of a stellar offensive line than he was a breakout college running back. He averaged 3.4 yards per carry during his NFL career, and his playing days ended for good when he landed in jail following multiple instances of assault. Even being in prison would not soften Phillips, as he has been accused of murdering his cellmate. Phillips is probably one of the worst people in NFL history.

12 12. Kevin Allen

The offensive tackle selected by the Philadelphia Eagles with the ninth overall pick of the 1985 NFL Draft was more than just a lousy blocker who didn't actually block much of anything during his single season in the NFL. Famous head coach Buddy Ryan once described Allen as being a good player “if you want someone to stand around and kill the grass.” Allen, the public would learn, was also a pretty lousy person. He was arrested on rape charges after the Eagles gave up on him in 1986 and he served nearly three years behind bars for that crime.

11 11. Jim Druckenmiller

You know how the San Francisco 49ers have a history of great quarterback play from men such as Joe Montana and Steve Young? Jim Druckenmiller did not follow in their footsteps. Selected with the 26th overall pick of the 1997 NFL Draft, Druckenmiller started a single game for the 49ers during his rookie season. That would be the only start of his NFL career. Druckenmiller completed 21 of 52 pass attempts in his debut campaign, but he did not attempt a single regular season pass the following season before he found himself out of San Francisco and ultimately out of the NFL. He did notch a single touchdown pass during his career, though, and nobody can take that away from him.

10 10. Bob Timberlake

A placekicker has to be particularly terrible to be mentioned among the worst players in NFL history. Enter Bob Timberlake, who was selected by the New York Giants in the third round of the 1965 NFL Draft. Timberlake buried the first field goal attempt of his pro career, but it all went downhill for him after that. He missed his following 14 – yes, 14 – attempts during the season, including two within the 30-39-yard range. That would prove to be enough for the Giants to give up on Timberlake after his failed rookie season and Timberlake never again played in the NFL.

9 9. Justin Blackmon

Perhaps Justin Blackmon has serious issues that need to be addressed before he permanently ruins his life. Maybe he is just a moron who doesn't care about abiding by NFL drug policies. Whatever the case, Blackmon sure seems to be a waste of NFL ability. The fifth overall pick of the 2012 NFL Draft has played in just 20 total games for the Jacksonville Jaguars, largely because he has been a mainstay on suspension lists. All indications from within the league are that the Jaguars have given up on him and his days in the NFL are seemingly finished.

8 8. Rusty Lisch

Rusty Lisch would be higher on this list if not for the fact that he probably never should have been considered to be a NFL player in the first place. The fourth-round pick of the 1980 NFL Draft was given an opportunity to play by the St. Louis Cardinals and he responded by tossing a single touchdown in four seasons with the club. That one score would be the only touchdown Lisch would throw among his 115 official NFL passes. For those who keep track of such stats, that makes for a 0.9 percentage of touchdowns thrown per recorded pass. Ugly.

7 7. Charles Rogers

Charles Rogers may be the biggest waste of talent on this list and that is saying something considering the players featured in this piece. The second overall of the 2003 NFL Draft flashed promise that he could develop into a top wide receiver, but his rookie campaign was over after just five games because of a broken clavicle. That was to be the beginning of the end of his NFL career. Rogers would appear in just ten games over the next two seasons before he became a lost cause due to his inability to follow the league's drug policy. More than just a draft bust, Rogers was a terrible player.

6 6. Cade McNown

Quarterback Cade McNown was a holdout during his rookie training camp in 1999, before the twelfth overall pick of that draft earned himself a $15 million contract that included a signing bonus worth $6 million. McNown rewarded the Chicago Bears with an average of eight touchdown passes per his two seasons with the club. He unfortunately matched that total by tossing 19 interceptions in that time. His NFL career was essentially finished even before the Bears gave up on him after two years, and he is now mostly forgotten except when fans mistakenly refer to him as “McCown” because it is just easier to say.

5 5. Ted Gregory

You can almost hear fans of the Denver Broncos sighing with sadness upon seeing the name of Ted Gregory. The famous story is that Denver head coach Dan Reeves was so horrified upon meeting his first-round pick that he yelled out, “I'm taller than he is!” Gregory, who had a bad knee upon joining the Broncos, was shipped to the New Orleans Saints before the start of the 1988 regular season. He played in just three games before his career came to an end. He is now a reminder for why coaches measure players multiple times at NFL Combines.

4 4. Art Schlichter

Odds are that Art Schlichter would never be the fourth overall pick in a NFL Draft these days when top-tier college players are watched by fans and media whenever they step out in public. That was not the case back in 1982, when it was hardly a secret that Schlichter had a taste for gambling. His taste grew into an appetite that consumed his career and also his personal life, and Schlichter was out of the league for good three years after he was drafted by the Baltimore/Indianapolis Colts. Schlichter couldn't overcome his demons despite efforts to do so and he is currently behind bars because of his involvement in a ticket scam that fleeced millions of dollars from victims.

3 3. Akili Smith

Nobody confused Akili Smith for Joe Montana when he was selected third overall in the 1999 NFL Draft. It would nevertheless be a massive understatement to say that Smith disappointed the Cincinnati Bengals with his play on the field. Smith had five touchdown passes during his NFL career. That's not a typo. He had five TDs. Finding the end zone five times is something that Peyton Manning has done on a solid Sunday afternoon. People may recall how poorly Tim Couch played for the Cleveland Browns, but make no mistake in knowing that Smith was much worse.

2 2. Ryan Leaf

There is a part of a sensible person that has to feel bad for Ryan Leaf. Leaf, the second overall selection of the 1998 NFL Draft, lacked the maturity and emotional stability required to play the most high-profile position in the NFL. Along with noteworthy outbursts at reporters inside of the locker room was a ratio of 14 touchdown passes to 36 interceptions that Leaf posted during his brief NFL career, one that has been followed by multiple legal issues and prison stints. Remembered only because of his terrible play and his personal woes, Leaf is undeniably one of the worst players in NFL history.

1 1. JaMarcus Russell

A young quarterback who is carrying some excess weight and who seemingly lacks motivation to be fully dedicated to the cause is compared to JaMarcus Russell. That will forever be the NFL legacy had by Russell. The first overall pick of the 2007 NFL Draft held out for more money, he started a single game during his rookie campaign, and he then bulked up in the worst way thanks in part to the millions of dollars he received after he signed his only significant NFL contract. This draft pick set the Oakland Raiders back several years and it is a selection that is often referred to as the worst in the history of the NFL. Russell earned his spot atop this list with his poor play and his lack of work ethic.