The Oakland Raiders haven't made the playoffs since their Super Bowl run back in 2002. That's also the last time the Raiders even had a winning record. The Raiders have a putrid record of 11-37 over the last three seasons.

Much of the reason for this is because of an unstable running game. Darren McFadden was constantly injured, and the Raiders ranked dead last in rushing yards last season. The signing of Trent Richardson doesn't bring much confidence to Raiders nation.

Here are five free agent running backs the Raiders should consider singing.

1. Steven Jackson

He's arguably the best player who is currently a free agent. Steven Jackson had 707 rushing yards with the Atlanta Falcons last season on a pass-first team. He's not the Jackson he once was that dominated with the St. Louis Rams, but it's the consistency that makes this investment worthy. The last two consecutive seasons Jackson has hit the six touchdown mark. Jackson has expressed a lot of desire to play with the Dallas Cowboys, but it doesn't appear as if Jerry Jones will make that signing. Jackson's stability could be a good signing for the Raiders given the fact that he has only missed six total games in the last five seasons.

2. Chris Johnson

Chris Johnson is fast, really fast. Despite not hitting the 1,000 yard mark for the first time in his career last season, he still averaged 4.3 yards per carry with the New York Jets. Johnson has the outside speed to open the field with Derek Carr connecting on passes in the middle. Johnson probably can't be the every down back he once was, but his speed and agility make this signing worth a try.

3. Ahmad Bradshaw

He may very well be the most clutch running back on this list. Ahmad Bradshaw was the leading running back in two Super Bowls for the New York Giants against the New England Patriots. Coincidentally, Bradshaw had to take over for Richardson last season on the Indianapolis Colts. Bradshaw isn't very fast, but he is consistent, and he can catch a lot of passes out of the backfield. The biggest issue here is health.

4. Knowshon Moreno

It's pretty sad what happened to Knowshon Moreno, but it's the risk of playing in the NFL. Twice in his young career Moreno has run for more than 940 yards in a season, but injuries have halted his performance. After a an excellent 2014 season in which he led the Denver Broncos to the Super Bowl with 1,038 rushing yards and 10 touchdowns, he found himself with the Miami Dolphins. Unfortunately for Moreno, he missed the majority of last season because of an ACL tear. Regardless of last year's injury, Moreno could be worth bringing in for the preseason on a veterans minimum. If the Raiders don't like what they see, they can simply cut him without any salary cap hits at all.

5. Pierre Thomas

Pierre Thomas and the Houston Texans were expected to strike a deal this week but were unable to agree on the terms. Thomas has played his entire career with the New Orleans Saints. In 2009 he helped the Saints win a Super Bowl rushing for 793 yards averaging 5.4 yards per carry. Thomas is a great north and south back who does his damage between the tackles. Even last season he averaged 4.9 yards per carry on a terrible Saints team. Thomas is a great teammate working with others posing a dual threat back combination.

Follow Damon Salvadore on Twitter @DamonSalvadore1