Posted by ESPN.com's Adam Rittenberg
1. Backs stacked -- Running back was a major question entering the spring, especially with Jaycen Taylor still rehabbing from a torn ACL. But sophomore Ralph Bolden came out of nowhere to spark the Boilers' rushing attack. Bolden capped an excellent spring with 153 rush yards and two touchdowns in the spring game. He finished with 420 rush yards in four spring scrimmages. Dan Dierking also performed well, and the running back spot should be deep once Taylor gets healthy and heralded freshman Al-Terek McBurse enters the mix.
2. Tight ends surge -- First-year head coach Danny Hope raved about his tight ends this spring, and the group will be featured more in the offense after a one-year hiatus. Projected starter Kyle Adams showed what he can do when healthy this spring, making 10 receptions in the spring scrimmages. He'll be pushed by both Jeff Lindsay and Jeff Panfil.
3. Defensive line solid -- Line play could be a strength on both sides of the ball, and the defensive front looked promising this spring. Defensive end Ryan Kerrigan appears ready to take another step after recording a team-high seven sacks last fall. He should get help from talented young players like Kawann Short and Gerald Gooden. Defensive tackle Mike Neal is very underrated inside and should have a big year.
1. Joey's time -- Senior quarterback Joey Elliott has waited his turn to start at quarterback, and barring a dramatic shift, he'll get it this fall. Still, Purdue would feel much more comfortable if Justin Siller was pushing Elliott for the top job. Siller might have been the team's No. 1 quarterback before his dismissal from school for violating academic policy. Elliott needs to elevate his game after three years as a backup, and Purdue must further develop backup Caleb TerBush.
2. Linebacker play -- There were some encouraging signs this spring, especially the re-emergence of oft-injured senior Jason Werner. But the rushing totals allowed in the spring scrimmages are troubling, and Purdue needs to identify three or four reliable linebackers after losing mainstay Anthony Heygood. The line and the secondary look solid, but linebacker is a bit iffy.
3. Wide receiver -- Purdue loses a ton of production at wide receiver, and Hope is still working to find capable targets for Elliott this fall. Keith Smith had a very solid spring and Aaron Valentin should take on a greater role this fall, but the Boilers need more bodies at receiver. They're hoping for more development this summer from converted cornerback Royce Adams.