Rookie running backs have a way of unexpectedly standing out in the preseason. They’re like the unknown friend of a friend who ends up being the life of the party. Half the time, the friend of a friend is intriguing only because he or she is a new face. It’s the same case with running backs. Some have just one enticing attribute––usually speed––that glistens in August around roster long-shots abbreviated playbooks. But some rookie runners show true potential. Here are three surprising running backs who have stood out thus far.

Justin Forsett, Seattle Seahawks

The one-year starter at Cal wasn’t drafted until the seventh round. With Julius Jones, Maurice Morris and T.J. Duckett already wearing Seahawk blue, Mike Holmgren has said that Forsett’s best chance at a roster spot is as a return specialist. Forsett looked great in Seattle’s second preseason game, punishing the Bears with two kick returns totaling 70 yards and five punt returns for 47 yards (he also had a 43-yard return called back for holding).

More intriguing was that the 5’8”, 194-pounder was a monster in the ground game. Forsett owned the second half and overtime, rushing 15 times for 136 yards and a touchdown. He has electrifying quickness and startling formidability after contact.

Because of injuries to Deion Branch and Bobby Engram, the Seahawks may have to sacrifice a running back slot on the 53-man roster for a wide receiver. If they do, they should cut Maurice Morris. After all, isn’t Forsett doing exactly what Morris has been unable to do for several years?

Tim Hightower, Arizona Cardinals

Drafted in the fifth-round out of Richmond, the bruising 226-pounder is primed to capture the No. 2 job behind Edgerrin James. Hightower has shown the dependability absent from former second-round pick J.J. Arrington. He’s also shown the burst absent from the Cardinals’ backfield. Hightower’s chemistry with Edgerrin James is fantastic (a dreadlock brotherhood, perhaps). Given the young runner’s tenacity and athleticism, it’s possible that James could be tutoring his own long-term replacement.

Chris Johnson, Tennessee Titans

Okay, unknown he is not. There are high expectations surrounding any first-round pick. But how many people were prepared for the fireworks of the faster-than-sound East Carolina product? Johnson is one of the few players whose stunning 40-time translates entirely on the field. Johnson’s speed takes virtually no time to maximize, and he shifts into a second gear the instant he breaks the line of scrimmage. When a player does this at the linebacker level, scouts call it a burst. When he does it before the linebacker level, scouts only stare. They can’t take their wide eyes off Johnson.

The Rest

Felix Jones has shown the big-play capabilities that Dallas covets. Matt Forte has solidified his starting job in Chicago (the mediocrity of Garrett Wolfe and Adrian Peterson has helped). Jacob Hester has gotten attention carrying the rock 25 times for San Diego. Kevin Smith remains ahead of Tatum Bell in Detroit, while Ray Rice has flourished with Willis McGahee on the mend. Not as impressive thus far but certainly worthy of excitement are Darren McFadden and Rashard Mendenhall, arguably the two most talented runners in this year’s rookie crop.