Riddick returned kickoffs as a freshman, played slot receiver the next two years and finished up at running back in his senior season when the Irish made it to the BCS national championship game.
Riddick's Notre Dame career didn't have a perfect ending. Alabama dominated Notre Dame from start to finish in a 42-14 victory that gave the Crimson Tide its third national championship in four years.
Riddick left South Bend knowing he was part of a team that restored Notre Dame to a position among college football's top teams.
"It was a great experience," he said in a conference call interview with the Detroit media. "You can't really put it into words. We were one game away from winning a national championship."
Riddick's versatility can help the Lions. As a freshman in 2009, he returned 37 kickoffs for a 22.9-yard average. He played slot receiver the next two seasons, and was used often as a receiver out of the backfield in 2012 when he moved to running back.
In his last three seasons, Riddick caught 114 passes and averaged more than 10 yards per catch all three years. He had eight receiving TDs.
Riddick had 54 carries in his first three seasons before moving to running back in 2012. He responded in 2012 with 190 carries for 917 yards and five TDs. He also caught 36 passes for 370 yards and two TDs.
"I've got some really close friends on the staff at Notre Dame," he said. "I lean on them."
Riddick can add more to the passing game than just catching dump-offs out of the backfield due to his experience of running routes downfield.
"He's been exposed to the whole (route) tree as a receiver," Modkins said.
Riddick is 5-10, 201 pounds and was timed in 4.66 seconds in the 40-yard dash. His 40 time indicates he'll have to win a job with his smarts and savvy rather than raw ability. He played at Immaculata High School in Manville, N.J.
Playing slot receiver at Notre Dame gave him a wider view of the offense than if he had played running back exclusively.
"It definitely gave me the ability to read a defense a lot quicker, catch the ball out of the backfield, feel comfortable doing it," he said. " Anyone can do it in practice, but when you're in a game, you've got (to have) a feel for things."
Riddick remembers watching Bush play at Southern Cal, where he won the Heisman Trophy in 2005.
"He tore it up," Riddick said. "To be in the same backfield would be unbelievable."