Professional football players know that they might be traded to another team for several reasons. Some trades inject new life into the organization, while others end up being a huge loss. These are ten of the worst trades ever made by NFL teams.

Randy Moss

The Oakland Raiders traded Randy Moss to the New England Patriots in April 2007. During his second year with the Raiders, Moss closed the year with low numbers, including 42 receptions for 553 yards and just three touchdowns. At the time, Raiders coach, Lane Kiffin, thought he had made a solid trade.

Moss' tenth year in the NFL was a career peak. At age thirty, Moss had 1,493 yards, the second-most yards of his illustrious career. He also had 23 touchdowns. This is still the NFL record for the most touchdowns by a wide receiver in a single season.

After almost tanking in his professional football career with the Raiders, Moss' career flourished with the Patriots. He would go on to become an NFL Hall of Famer.

Steve Largent

In 1976, the Houston Oilers chose University of Tulsa's Steve Largent in the fourth round of the NFL Draft. The next year, the Oilers traded him to the Seattle Seahawks. It looked like his career might end before it ever got started.

Once he had joined the Seahawks, Largent's career began to take off, thanks to his sure hands. In 1978, he was chosen for the Pro Bowl, which he was selected for another six times during his 14 years with the Seahawks. He broke Charlie Joiner's record for receiving yards in 1988, with 12,146 yards in the third week of the year.

When Largent retired from the NFL, he held every major receiving record. This includes most career receptions, most career receiving yards, and most touchdown receptions. He also held the then-record of 177 consecutive regular season games with a reception. He was also the first receiver in NFL history to have 100 career touchdown receptions.

Jerry Rice

This trade is a lesson in not believing in the numbers. In 1985, the Patriots thought they made a good trade by exchanging their 16th pick for numbers 28 and 56 of the 49ers. What they actually did, however, was trade away one of the best football players that ever played the game.

When Rice retired from the NFL, he held career records for receiving yards, touchdowns, and receptions. He won three Super Bowls.

John Elway

In 1983, the Baltimore Colts made John Elway their number one draft pick. This would have been great, except for one thing; Elway had previously stated that he would not join the team. He was traded to the Denver Broncos in 1984.

To give you an idea of what an all-around great player Elway was, he alone was responsible for 334 touchdowns, scoring 82.2% of the Broncos total 5,806 points during his 16 years with the team.

Brett Favre

Quarterback Brett Favre was drafted by the Atlanta Falcons in 1991. Following a less-than-stellar season, the Falcons traded him to the Green Bay Packers.

This turned out to be the worst trade the team ever made. Favre would go on to be in the Hall of Fame and was voted the league MVP for three consecutive seasons during his 16-year career with the Packers.

Jerome Bettis

In April 1996, the St. Louis Rams traded Jerome Bettis to the Pittsburgh Steelers. This is thought to be one of the best things to happen to the Steelers in a long time.

Bettis was added to the Pro Football Hall of Fame in 2015. During his time with the Steelers, he rushed for 10,571 and had a total of 13,662 career yards.

Ryan Leaf

In 1998, the Los Angeles Chargers got Ryan Leaf from the Arizona Cardinals. The Cardinals thought quarterback, Jake Plummer, would be all they needed, so they didn't think much of the loss. Leaf had a dismal 39.0 QB rating in 1998.

In his four years in the NFL, Leaf has a career total of 3,666 yards and 14 touchdowns.

John Hadl

When the Packers traded for the Los Angeles Rams' John Hadl in 1974, they made one of the best moves ever. The Rams, however, lost out big.

Hadl had a career total of 244 touchdowns, 268 interceptions, and 33,503 yards. This College Hall of Famer was an All-Star four times and was chosen for two Pro Bowls.

Ricky Williams

Before the 1999 NFL draft, the Washington Redskins traded Ricky Williams, a Heisman Trophy winner, to the New Orleans Saints.

Williams would go on to achieve 10,009 yards and 66 touchdowns during his career.

Herschel Walker

This Heisman Trophy winner was traded by the Minnesota Vikings to the Dallas Cowboys in 1989. During his career he would earn 8,225 yards and scored 61 touchdowns.