Adonis Smith's decision to transfer from Northwestern might not mean much come September.

But his exit adds to the questions surrounding a position that hasn't provided enough definitive answers in the past few seasons.

Smith appeared in 17 games the past two seasons, racking up 462 rush yards and three touchdowns. He might have evolved into the Wildcats' featured back, but he also might have been a career backup. It's tough to tell. Coach Pat Fitzgerald announced Smith's departure Wednesday.

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Jerry Lai/US PRESSWIRERunning back Adonis Smith has decided to transfer from Northwestern.

"We're disappointed to see Adonis leave Northwestern," Fitzgerald said in a statement. "He is an outstanding young man and we wish him nothing but the best in his future endeavors."

Wildcats fans will forget about Smith if, say, Mike Trumpy returns from a torn ACL and surges as the starter. Or if true freshman Malin Jones emerges in preseason camp. Or if Treyvon Green builds on a freshman season in which he rushed for 362 yards and four touchdowns.

But if Northwestern can't identify a featured back and fails to generate a consistent rushing attack in 2012, Smith's name likely will be brought up.

While a struggling defense should be coach Pat Fitzgerald's top priority in the offseason, running back shouldn't be too far down his checklist. Northwestern's offense has made strides under Fitzgerald's watch, producing a steady stream of quarterbacks and wide receivers in recent years. But the running back position, once a program strong point, has declined.

Fitzgerald's predecessor at Northwestern, the late Randy Walker, left an indelible mark on the position he played in college. Walker had a 1,000-yard rusher in 25 of his 30 seasons in coaching, including each of his final four seasons as Northwestern's head coach (2002-05). Northwestern produced a 1,000-yard rusher in five of Walker's final six seasons.

But since Tyrell Sutton finished with exactly 1,000 yards in 2006, Fitzgerald's first season as Wildcats coach, Northwestern has failed to produce a 1,000-yard rusher.

Here are the team's leading rushers the past five seasons:

• 2007: Sutton, 451 yards
• 2008: Sutton, 890 yards
• 2009: Arby Fields, 302 yards
• 2010: Trumpy, 530 yards
• 2011: Kain Colter, 654 yards

Colter, by the way, plays quarterback for the Wildcats. Fields transferred following a disappointing 2010 season when he struggled to hang onto the ball or a favorable spot on the depth chart.

Why can't Northwestern produce featured backs anymore? An offense rooted in high-percentage passes and accurate quarterbacks has something to do with it. But the Wildcats have run the spread since 2000, and it didn't stop them from producing standout backs under Walker.

Northwestern has run the ball better as a team the past two seasons, rising from 95th nationally in rushing in 2009 to 58th in 2010 and 45th in 2011. But the team had a league-low 3.8 yards-per-carry average last fall.

Jones, the team's first commit in the 2012 recruiting class, could be the answer, much like Sutton was in 2005, when he captured Big Ten Freshman of the Year honors. Perhaps Trumpy bounces back from injury or Green takes steps in his development. Maybe a committee system is the best approach.

If not, you might hear some grumbling about Adonis Smith in September.