Spring football has begun in Norman, Okla.

Several playmakers return, but some unknown players could make names for themselves during March and April. Here are five to keep an eye on:

Defensive tackle Charles Walker: Unlike a year ago, the Sooners aren’t searching for experienced playmakers on the defensive line. OU returns six defensive linemen who started a game in 2013, yet few people around the program would be surprised if Walker earns playing time as a redshirt freshman this fall.

“Charles has really been impressive,” OU coach Bob Stoops said. “He had a great fall. He’s a guy that’s up to about 300 pounds now, light on his feet, ran really well when we timed. I want to say he ran in the 4.7s, so he really has a bright future. [He] works hard. Charles is going to be a big factor in that defensive line.”

Receiver Derrick Woods: It’s taken a while for Woods to get comfortable as a receiver after stepping on campus as a multi-dimensional athlete who played several positions in high school. But his special-teams role as a freshman affirmed his place as one of the better athletes on the team, and his 20-yard catch in the Sugar Bowl could be a sign he’s ready to make an impact at receiver.

“[Woods] has really come on,” Stoops said. “Derrick Woods made a huge play in the Sugar Bowl when we had to have it on a third-and-12 or whatever it was -- a competitive play.”

Defensive end Mike Onuoha: The sophomore was mentioned along with Charles Tapper as the future of the Sooners defensive line after both youngsters played themselves out of a redshirt season in 2012. Last season, Tapper fulfilled his upside, earning All-Big 12 honors; Onuoha watched from the sideline after shoulder surgery. This spring is Onuoha’s chance to make his mark. He brings unique size and athleticism at 6-foot-5 and 249 pounds.

“Michael Onuoha really is a guy ready to make a big move in that defensive line,” Stoops said.

Receiver Jordan Smallwood: As soon as Smallwood stepped on campus last summer, he began impressing teammates with his physical nature and receiving skills. A foot injury took away his freshman season, but he returned to practice during Sugar Bowl preparations and drew praise from the coaches. This spring is his chance to show he can be a big part of OU’s offense in 2014.

“They finally turned him loose to practice in the bowl practices,” Stoops said. “[He] really was impressive.”

Linebacker Devante Bond: Much like Walker, OU doesn’t need Bond to make an impact with playmaking veterans returning at linebacker. However, if he shows the pass-rushing prowess he displayed in junior college, he could become a key component of the Sooners’ defense in pass situations, joining Eric Striker to create havoc in opponent’s backfields.

“Devonte Bond has really looked impressive in our workouts and weights,” Stoops said. “In long yardage he will put his hand down and let him go or stand him up and let him go.”