Fernando Valenzuela Before "Linsanity," there was Fernandomania. In 1981, a 21-year-old rookie pitcher from Mexico took Major League Baseball by storm. Fernando Valenzuela, a hefty lefty who pitched for the Los Angeles Dodgers, started his rookie year with eight straight wins, becoming a media darling and a Latino sports icon in the process. At the end of the season, Valenzuela would go on to win the National League Rookie of the Year award and the National League Cy Young award (top pitcher in the league).

Victor Cruz "I was going to be another inner-city kid working at Wendy’s or some mall." New York Giants wide receiver Victor Cruz knew that he was only a mistake or two away from missing his chance of NFL stardom. Cruz had a rollercoaster football career at UMass, where he struggled to keep his grades up and lost his scholarship. After the death of his father, Cruz hit the books and finished school, but went undrafted in 2010. The New York Giants took a chance on Cruz, and the half-Puerto Rican receiver delivered, setting a franchise record for receiving with 1,536 yards.

Mike Piazza In 1988, the Los Angeles Dodgers selected a virtual unknown named Mike Piazza during the 62nd round of the MLB draft. Then-manager Tommy Lasorda selected Mike Piazza as a favor to Mike's father, Vince Piazza, who grew up with Lasorda. Orignally a first baseman, Mike Piazza was asked to become a catcher. The move worked, as Piazza went on the become one of the most decorated catchers in MLB history, including a 1993 Rookie of the Year award and 12 All-Star appearances.

Arian Foster A standout at Tennesse, Foster went undrafted in 2009 because scouts thought he was too slow to succeed in the NFL. A year later, Foster earned the starting job. In his first start for the Texans, Foster racked up a record-breaking 231 yards and scored three touchdowns. By the end of the season, Foster was the NFL rushing champ.

JJ Barea Despite a solid college basketball career at Northeastern University, Puerto Rican baller José Juan Barea went undrafted in 2006. He was eventually signed by the Dallas Mavericks, where he worked his way up from being the team's third string point guard to backing up future hall of fame point guard Jason Kidd. Barea proved his worth during the Mavs' 2011 championship run, where his speed and agility killed defending champs the Los Angeles Lakers. In the NBA Finals, Barea shined once again, scoring 15 points in Dallas' championship-clinching game versus the Miami Heat.

Wes Welker At 5'9," 185lbs, wide receiver Wes Welker had a hard time getting a college football scholarship. After a record-breaking career at Texas Tech, Welker couldn't find a team that would draft him. The San Diego Chargers took a chance on Welker but cut him after just one game. He was snapped up by the Miami Dolphins, where it took three seasons for Welker to establish himself as a go-to receiver. In 2007, Welker signed with the New England Patriots. Despite standing much shorter than most contemporary NFL wide receivers, Welker became a star after becoming one of Tom Brady's favorite targets.

Fred Jackson Running back Fred Jackson attended Texas high school football powerhouse Lamar High School but he never got a chance to start a varsity game. Unable to get a college scholarship, Jackson took his talents to Coe College (Cedar Rapids, Iowa), which fielded a Divison III football program. In the 2003 NFL Draft, Jackson, who was considered too small (6'1, 215lbs), was once again overlooked. Jackson settled on playing indoor football for two years before playing in the now-defunct NFL Europe league. In 2006, Jackson finally got his chance to play in the NFL after signing with the Buffalo Bills. In 2009, Jackson had a breakthrough season, rushing for over 1,000 yards and scoring four touchdowns. In 2011, Jackson, who was by then considered "too old" to be effective, was having the best season of his career before an injury cut his season short.

Nyjer Morgan A former hockey player, San Francisco, California native Nyjer Morgan hung up his skates to play pro baseball. Morgan spent five years in the minors before getting called up by the Pittsburgh Pirates in 2007. Two years later, Morgan became a fan favorite in Pittsburgh for his defensive skills and knack for stealing bases. In 2011, Morgan's clutch performances for the Brewers made him a fan favorite in Milwaukee as well.

Antonio Gates A standout basketball player at Kent State University, Antonio Gates had dreams of playing in the NBA. But at 6'4", 260lbs, he was considered to be too big for a guard and too small to be a forward. He went undrafted in the 2003 NFL draft but eventually signed a deal with the San Diego Chargers, who were banking on Gates' size to make him a solid tight end. The Chargers were right: after his rookie season, Gates has made eight straight pro bowls and is considered an elite NFL tight end.

Ben Wallace Ben Wallace was an undrafted NBA benchwarmer who saw little time during his first two seasons with the Washington Bullets (now the Washington Wizards). In 1999, Wallace was traded to the Orlando Magic, where he spent just one season before being traded to the Detroit Pistons. Wallace flourished in Detroit, where the 6'9" center developed into a dominant defensive player despite his relative lack of height (at his position). In 2004, Wallace helped lead the Pistons to a NBA Championship over the favored Los Angeles Lakers.

James Harrison In high school, Linebacker James Harrison was a prep football star with "maturity issues." Those issues, such as making obscene gestures to fans and pointing a BB gun at a coach, made big-name college programs wary of recruiting Harrison. After completing his college career at Kent State University, Harrison went undrafted in 2002. At 6'0" and 242 lbs, Harrison was deemed to small to be an effective NFL linebacker. He bounced around for two years before settling with the Pittsburgh Steelers. Harrison began establishing himself as a part of the Pittsburgh's tough defense and eventually became a star linebacker for the Steelers. Despite becoming a five-time pro bowler and two-time Super Bowl champ, Harrison's "maturity issues" have continued to plague him in the pros.

Tony Romo After graduating from Eastern Illinois University, Tony Romo went undrafted in 2003 but earned a third string quarterback spot with the Dallas Cowboys. Romo was on the verge of being cut from the team until fellow QB Quincy Carter was dropped for failing a drug test. In 2006, Romo worked his way up to a starting position on "America's Team" and helped the Cowboys reach the playoffs. Romo was named to the Pro Bowl that same year, as well as the following two seasons.

John Starks (pictured with Isiah Thomas) After getting busted for smoking weed in his Northern Oklahoma college dorm, Tulsa native John Starks was working at a supermarket and going to his local community college. Two years later, he was playing for the New York Knicks, one of the NBA's marquee franchises. Starks went on to become a fan favorite in New York, where he teamed up with Patrick Ewing to battle Michael Jordan and the Chicago Bulls in the NBA playoffs.

Kurt Warner After going undrafted in the 1994 NFL draft, quarterback Kurt Warner got a tryout with the Green Bay Packers – home to future Hall of Famer Brett Favre. Warner was dropped during the preseason and took a job bagging groceries in his local supermarket. Warner played four years of arena football before getting a call from the St. Louis Rams in 1998. A year later, Warner led the Rams to their first Super Bowl victory, where he was named MVP. Warner also ended his dream season with an NFL MVP award.