Spring primer: Oklahoma Sooners

Mark Andrews had seven touchdown receptions in 2015 and is expected to have a bigger role in Oklahoma's offense this fall. Mark D. Smith/USA TODAY Sports

Oklahoma is kicking off spring practice Saturday.

Below is a preview of what to look for from the Sooners this spring:

Offensive returner ready to take next step: Bob Stoops said Thursday that tight end Mark Andrews "will have a bigger role" in the offense next season. With Sterling Shepard moving on to the NFL, the Sooners will be looking for a go-to receiver to take his place. After breaking out with seven touchdowns last year, Andrews could be one of those primary options.

Defensive returner ready to take the next step: Though he was overshadowed by Charles Tapper and Eric Striker, Charles Walker quietly was one of most disruptive defensive linemen in the league last year. The Sooners sorely missed his presence when he had to sit out with a concussion in the Capital One Orange Bowl. Walker has the talent to be a first-team All-Big 12 performer. With Tapper and Striker no longer around, the Sooners are banking he can become just that.

Redshirt freshman to watch: With two starting receivers gone, the opportunity for playing time will be there for OU's younger receivers. Jeffery Mead and Jordan Smallwood, among others, figure to vie for those open slots in the rotation. But keep an eye on John Humphrey, a former ESPN 300 signee whom the Sooners beat out Notre Dame for. Humphrey needed the redshirt year to put on size. But he has the explosiveness to give OU another playmaker.

Most significant position battle: The cornerback spot opposite Jordan Thomas will be the position to watch this spring, as Dakota Austin, P.J. Mbanasor and Will Johnson will all be competing for the job vacated by All-Big 12 cornerback Zack Sanchez. Austin played well in two starts last year. Mbanasor is a former ESPN 300 signee. Johnson started at nickelback midway through the season.

Key midterm enrollee: With Cody Thomas giving up football to play baseball and Texas A&M transfer Kyler Murray not eligible until 2017, the Sooners will probably be leaning on incoming freshman QB Austin Kendall to back up Baker Mayfield next season. The good news is that Kendall is already enrolled and will have the spring to take in OU's system. Said Stoops: "He's a talented guy. Just watching him out there running around with our players, he fits in. He doesn't look behind at all physically. So we just have to get time on the field with him.”

Question that could be answered: The Sooners graduated a pair of standout offensive linemen on the interior in Ty Darlington and Nila Kasitati. But coming out of the spring, offensive line coach Bill Bedenbaugh should have a pretty good feel for what his rotation will look like in the fall. Jonathan Alvarez will get the first crack at center after manning guard last year. And though Alex Dalton will still be working his way back from a knee injury, others like Jamal Danley, Ashton Julious, Cody Ford, Ben Powers, Christian Daimler and Bobby Evans will get a chance to show what they can do this spring.

Question that won't be answered until fall: How exactly will the Sooners replace the production that Shepard supplied the past two years? That's just not something they can know until they get into the season. There's plenty of talent at the position. But it largely remains unproven. And OU won't know who exactly it will be able to count on until the lights come on in the fall -- and those receivers are placed in pressure-packed situations.