Posted by ESPN.com's Adam Rittenberg
1. Matthews impresses -- The competition at running back remains open entering the summer, but speedy sophomore Jeravin Matthews made a strong push this spring. One of only two true freshmen to see the field last fall, Matthews moved from wide receiver to running back and brings top-end speed to the backfield. He had a game-high 90 yards and a touchdown in the spring scrimmage.
2. Backers set -- Northwestern left the spring with its starting linebacking corps set. Middle linebacker Nate Williams and strong side backer Quentin Davie were likely starters following the 2008 season, and Ben Johnson emerged at the weak-side spot in practice. Johnson has impressed head coach Pat Fitzgerald with his speed on the outside.
3. O-line develops -- With several skill positions up in the air, Northwestern will lean on a line that returns four starters. Left tackle Al Netter and center Ben Burkett anchor the group after turning in solid performances this spring. Northwestern has recruited better to offensive line than any other position, and several redshirt freshmen (Neal Deiters, Brian Mulroe, Nick Adamle) will provide depth.
1. Wootton's health -- All eyes will be on All-Big Ten defensive end Corey Wootton this summer as he returns from a torn ACL. Reports on Wootton's rehab are promising, but there's no certainty he will return to the form he showed last season. Wootton projects as a first-round draft pick if healthy, and Northwestern needs him to anchor the pass rush in 2009.
2. Quarterback competence -- Mike Kafka has proven himself as a runner, but his consistency as a passer remains a question entering the summer. Kafka has a so-so spring and still must improve on the short to intermediate routes that spur Northwestern's offense. Coordinator Mick McCall has a good track record of developing quarterbacks, but both Kafka and backup Dan Persa need to make a jump this summer.
3. Receiver rotation -- The wide receiver depth chart is written in pencil at this point, and several spots might not be settled until the Sept. 5 opener. Andrew Brewer seemed better suited to the outside receiver spot this spring, but Northwestern will need another option or two to emerge inside alongside Jeremy Ebert, who returns from a hip injury.