5 undrafted free agents in NFL history ft. Kurt Warner 

At the conclusion of the NFL Draft each year, some college football players who weren't selected get signed by teams as undrafted free agents. These players are speculative adds to their new teams. Many of them fail to make the roster, while some remain on the practice squad.

Every once in a while, an undrafted free agent makes the team and eventually goes on to become a legend of the game. Here are five of the greatest players to do so.

Legendary undrafted free agents from NFL history

#5 - Antonio Gates

Antonio Gates was a highly-recruited football and basketball player when he was in high school. He decided to pursue a basketball career and chose not to play football. At the conclusion of his college playing days, he realized he likely wasn't going to make it to the NBA, so he tried out for the San Diego Chargers, who immediately signed him to the roster.

Gates went on to become one of the greatest tight ends of all-time. At the peak of his career, he was selected to eight consecutive Pro Bowls while also being chosen for five All-Pro teams. He will likely be selected to the Pro Football Hall of Fame when he becomes eligible.

#4 - James Harrison

James Harrison went undrafted in the 2002 NFL Draft before being signed to the Pittsburgh Steelers' practice squad. He struggled to make the roster for several years before eventually becoming a starter for the 2007 season.

Harrison immediately became one of the most dominant pass rushers in the league, making four consecutive All-Pro teams and five-straight Pro Bowls. He was also selected as the 2008 Defensive Player of the Year while helping the Steelers win two Super Bowl rings.

Great undrafted free agents from NFL history

#3 - Priest Holmes

Priest Holmes was signed as an undrafted free agent by the Baltimore Ravens following the 1997 NFL Draft. He earned the starting running back job for the 1998 season, but only kept it for one year. A couple of years later, he was signed by the Kansas City Chiefs prior to the 2001 season.

Holmes put together one of the best three-year stretches in NFL history. He was selected as a first-team All-Pro for three consecutive seasons and won the 2002 Offensive Player of the Year award. He twice led the league in total yards and total touchdowns while setting an NFL record with 27 rushing touchdowns. Unfortunately, a spinal injury cut his career short.

#2 - Warren Moon

Warren Moon decided to join the CFL after going undrafted in the 1977 NFL Draft. He found a ton of success during his six seasons there, leading the Edmonton Eskimos to five consecutive Grey Cup championships.

Moon joined the Houston Oilers prior to the 1984 season and continued his successful football career with three different teams. He is a member of the Pro Football Hall of Fame while currently ranking 13th in career passing yards and 16th in passing touchdowns.

#1 - Kurt Warner

Kurt Warner was signed as an undrafted free agent by the Green Bay Packers following the 1994 NFL Draft. He was cut from the team prior to the start of the season, so he joined the Iowa Barnstormers of the Arena Football League. After dominating the AFL, he was signed by the St. Louis Rams, prior to the 1998 season.

Warner spent a year as a back-up before getting his opportunity to become the starting quarterback. He put together one of the greatest three-year stretches of all-time, winning two NFL MVP awards and a Super Bowl ring. Warner would later help the Arizona Cardinals reach the Super Bowl, as well, before eventually being selected to the Hall of Fame.