Undrafted out of Kent State in 2002, the 6-foot Harrison was cut four times before landing a gig as a Steelers wedge buster in '04. Harrison became a starting Pittsburgh linebacker three seasons later; in '08 he was the Defensive Player of the Year.
In 2004 the 5'9" rookie receiver was cut by the Chargers before joining Miami, where over three seasons he returned 293 kicks and punts and even made a field goal. Traded to the Patriots in '07, Welker became a five-time Pro Bowl receiver.
The free safety spent his first two years on the Cowboys' special teams unit before becoming a starter in 1995. He would play nine more seasons with Dallas, the Dolphins and the Lions, all as a starter, while also returning kicks most of the time.
A fourth-round draft pick from Kansas State in 2005, Sproles began his career as a returner and backup running back for the Chargers. Despite being 5'6", he has developed into one of the league's most dangerous all-purpose runners.
The lightning to Larry Csonka's thunder was a returner for Miami before earning three Pro Bowl nods as a running back. In 1969, his rookie year, Morris led the AFL in kick-return yards (1,136) and was second in combined kick and punt returns (68).
An undrafted free agent from Rutgers, Brackett made 25 special teams tackles for the Colts in 2003, his rookie season. He was the their starting middle linebacker by '05 and the heart of Indy's defense until he retired in '11.
BOB ROSATO/SPORTS ILLUSTRATED (HARRISON)
BOB ROSATO/SPORTS ILLUSTRATED (WELKER)
BOB ROSATO/SPORTS ILLUSTRATED (SPROLES)
BILL HICKEY/ALLSPORT/GETTY IMAGES (MARION)
FOCUS ON SPORT/GETTY IMAGES (MORRIS)
AL TIELEMANS/SPORTS ILLUSTRATED (BRACKETT)