Wide receiver Rod Smith -- After joining the Broncos' practice squad in 1994, Smith played on two Super Bowl winning teams in 1998 and 1999 and went on to become the franchise record holder for career receptions (849), receiving yards (11,389), touchdown catches (68), touchdowns (71) and 100-yard games (31). The Missouri Southern product also leads all undrafted players in every major receiving category. (Photo by Jonathan Daniel/Getty Images)

Dick "Night Train" Lane -- Joined Rams in 1952 as a free agent after four years in the Army and went on to set an NFL record for interceptions with 14. Over his 14-year career, Lane intercepted 68 passes. Lane was inducted into the Pro Football Hall of Fame in 1974.
» Video: Lane retrospective (Photo by NFL/NFL)

Center Jeff Saturday -- Originally signed by the Ravens as an undrafted free agent in 1998, Saturday found a permanent home with the Colts in 1999, starting in 128 of 137 appearances since. In nine seasons with Indianapolis, Saturday has earned three Pro Bowl selections while also helping the Colts to a Super Bowl victory in 2006.

Lou Groza -- "The Toe" Groza's last-second field goal in the 1950 NFL title game earned the Browns a championship in their first season in the league. In all, Groza -- who also played offensive tackle -- scored 1,608 points in 21 years and remains an unforgettable symbol of a bygone era when roster limits prevented kickers from being specialists. (Photo by Frank Rippon/NFL)

Quarterback Jake Delhomme -- Louisiana's all-time passing leader spent one season on the Saints practice squad and two seasons playing in NFL Europa before earning a roster spot with the Saints in 1999. After signing with the Panthers in 2003 Delhomme beat out Rodney Peete to become the team's starter, ultimately leading the Panthers to the Super Bowl that season. (Photo by Doug Benc/Getty Images)

Marion Motley -- One year before Jackie Robinson made his debut with the Brooklyn Dodgers, Hall of Famers Motley and teammate Bill Willis debuted with Paul Brown's Cleveland Browns in the AAFC. Motley was the AAFC's all-time leading rusher and helped the Browns win the 1950 NFL championship.
» Video: Motley retrospective (Photo by Frank Rippon/NFL)

Kicker Adam Vinatieri -- After a stint with the Amsterdam Admirals of the World League of America, Vinatieri signed with New England Patriots in 1996 and spent 10 years with the club, playing in four Super Bowls and earning a reputation as one of the best clutch kickers in the NFL. (Photo by Andy Lyons/Getty Images)

Linebacker Antonio Pierce -- Originally signed as an undrafted free agent by the Redskins in 2001, Pierce was signed by the Giants as an unrestricted free agent in 2005 and helped the team to a victory in Super Bowl XLII. Pierce has led the Giants in tackles the past two seasons. (Photo by Nick Laham/Getty Images)

Bill Willis -- As a two-way star for the original Browns from 1946-1953, Willis excelled on defense, which included a famous tackle that helped preserve the Browns' title drive in 1950. Willis was inducted into the Pro Football Hall of Fame in 1977.
» Video: Willis retrospective (Photo by Pro Football Hall Of Fame/NFL)

Running back Priest Holmes -- In 1997, University of Texas product Holmes signed with the Baltimore Ravens, a club with whom he won a Super Bowl ring. In 2001, he signed with the Chiefs and finished the season as the league's leading rusher. Holmes went to the Pro Bowl three times but his career was cut short by a spinal cord injury in 2005. (Photo by Jamie Squire/Getty Images)

Warren Moon -- Banished to the CFL after going undrafted, Moon emerged in the NFL in 1984 and went on to produce nine 3,000-yard passing seasons and four 4,000-yard passing seasons in a 17-year career with the Oilers, Vikings, Seahawks and Chiefs.
» Video: Moon retrospective (Photo by Allen Kee/NFL)

Running back Willie Parker -- Parker was used sparingly at the University of North Carolina, ultimately getting passed over in the 2004 NFL Draft. Parker joined the Steelers as an undrafted free agent that year and earned a starting spot the following season, helping the Steelers to a victory in Super Bowl XL. (Photo by Rick Stewart/Getty Images)

Quarterback Kurt Warner -- Warner spent three seasons playing with the Iowa Barnstormers in the Arena Football League and one season with NFL Europa's Amsterdam Admirals before starting all 16 games for the Rams as an undrafted free agent in 1999. Warner went on to win the first of his two MVP honors that season and led the Rams to two Super Bowl appearances in 2000 and 2001. (Photo by Harry How/Getty Images)

Defensive end Paul Spicer -- After graduating from Saginaw Valley State University, Spicer joined the CFL's Saskatchewan Roughriders. In 1999, Spicer signed with the Detroit Lions as a member of the practice squad. The next season he became a member of the Jaguars, where he recorded 7.5 sacks in both 2005 and 2007. (Photo by Sam Greenwood/Getty Images)

Quarterback Jon Kitna -- After Kitna led the Barcelona Dragons to the 1997 World Bowl championship, the Seattle Seahawks came calling and Kitna spent the next four seasons with the club. He moved on to Cincinnati for five seasons before becoming the Lions starter in 2006. (Photo byGregory Shamus/Getty Images)

Running back Selvin Young -- A week after being passed over in the 2007 draft, Young signed a contract with the Denver Broncos. When starter Travis Henry went down with an injury, Young stepped in a finished the season with 729 yards on the ground and is expected to be on top of the depth chart in 2008. (Photo by Steve Dykes/Getty Images)

Quarterback Jeff Garcia -- Garcia played five seasons with the Calgary Stampeders in the Canadian Football League before signing with 49ers in 1999. He played in 13 games with 10 starts that season and went on to become the team's full-time starter through 2003. Garcia has since gone on to start for the Browns, Lions, Eagles and Buccaneers. (Photo by Al Messerschmidt/Getty Images)

Quarterback Tony Romo -- Signed by the Cowboys as an undrafted free agent in 2003, Romo earned himself a roster spot as the team's third quarterback. The Eastern Illinois product made his first start Oct. 29, 2006 when Cowboys starter Drew Bledsoe went down with an injury. Romo went on to become the Cowboys' first Pro Bowl quarterback since Troy Aikman after leading the Cowboys to six victories and a playoff berth in 10 starts in 2006. (Photo by Chris Graythen/Getty Images)

Running back Ryan Grant -- Grant wasn't drafted out of Notre Dame in 2005, but the Giants signed him to their practice squad. Before the start of the 2007 season, Grant was traded to the Packers. He became the starter midseason, turned the Green Bay's running game around and finished the season with five 100-plus yard games. (Photo by Jamie Squire/Getty Images)

Emlen Tunnell -- During the 1950s, the Giants were a perennial contender and Tunnell was a key contributor for the Giants' talented defenses of that era. Tunnell became the first African American to be elected to the Pro Football Hall of Fame when he was inducted in 1967. (Photo by Pro Football Hall Of Fame/NFL)

Frank Gatski -- A 1985 inductee into the Pro Football Hall of Fame, Gatski anchored the offensive line for a Browns team that played in 11 championship games in 12 years (winning seven; four AAFC titles, four NFL titles). He was then traded to the Lions in 1957, where he helped the Lions win their last NFL championship. (Photo by Frank Rippon/NFL)

Wide receiver Wes Welker -- A four-year letterman at Texas Tech, Welker was originally signed by the Chargers as an undrafted free agent in the spring of 2004, only to be waived that September and signed by the Dolphins. Welker became the Dolphins' leading receiver in 2006 (67 receptions) before he was traded to the Patriots, where he tied for the league lead in receptions (112) in 2007. (Photo by Ben Liebenberg/NFL Photos/Getty Images)

Tight end Antonio Gates -- Gates averaged 20.6 points and 7.7 rebounds in his senior season at Kent State with his sights set on the NBA Draft. But with his options ultimately limited in the NBA, Gates concentrated on football, despite not having put on pads since his senior year of high school. Since joining the Chargers in 2003 Gates has been one of the most prolific tight ends in the league, recording 340 receptions and 43 touchdowns in five seasons. (Photo by Chris McGrath/Getty Images)

Larry Little -- A guard who helped pave the way for the Dolphins' powerful running game of the 1970s, Little was All-Pro six times and selected to the Pro Bowl five times. Little was a 1993 inductee into the Pro Football Hall of Fame. (Photo by Sylvia Allen/NFL)

Jim Langer -- Signed as an undrafted free agent in 1970, many considered Lange to be the most proficient performer on a talent-laden Dolphins offensive line. Langer was a 1987 inductee into the Pro Football Hall of Fame. (Photo by NFL/NFL)

Joe Perry -- After having played at Compton Junior College, Perry was signed by the 49ers in 1948 and eventually became a member of the team's famed "Million Dollar Backfield" that also included Hall of Famers John Henry Johnson and Hugh McElhenny. Perry became the first player in NFL history to rush for 1,000 yards in consecutive seasons (1953-54). (Photo by NFL/NFL)

Willie Wood -- A 1989 inductee into the Pro Football Hall of Fame, Wood played in six NFL championships -- including Super Bowls I and II -- for Vince Lombardi's legendary Packers teams of the 1960s. (Photo by NFL/NFL)

Emmitt Thomas -- Thomas amassed a Chiefs-record 58 career interceptions in a 13-year career with the team. Thomas also had an interception in the Chiefs' victory in Super Bowl IV. Thomas is a 2008 inductee into the Pro Football Hall of Fame. (Photo by Rod Hanna/NFL Photos/Getty Images)