The outside linebacker redshirted his freshman season with the Trojans and was used sparingly in his second year as he battled nagging injuries.
Through spring ball, Starr has made himself a staple with the Trojans defensive line rushing off the edge. He's even drawn cheers from teammates at multiple practices inflicting bruising hits on the offense.
Starr told Scout that this his time to step up.
Both Kennard and Breslin, outside linebackers, graduated after the 2013 season.
"That's how I'm looking at it – now is my time," Starr said.
"Scott is having a really good spring," defensive line coach Chris Wilson said. "He has been available for every practice and he's improved every practice."
Starr, 6-foot-2 220-pounds, is also starting to look the part of a college veteran. "I just feel like I'm developing into a man's body," he said. "I was a little kid when I first got here but now I'm getting older, stronger, and quicker."
He spent much of the spring taking first team reps alone before the return of senior J.R. Tavai, who he'll battle for the starting spot when fall camp opens.
"It's going to be a hard competition with JR," Starr said. "JR is a beast in my opinion, everybody knows that. So it's going to come down to whoever the coaches feel best with but I know we'll both make contributions."
"I'm really excited about the competition [Starr] and JR Tavai are creating," said Wilson. "Both of them are playing at a high level and both of them are capable of helping us compete in the Pac-12."
USC's defense has undergone many changes and has been forced to make multiple adjustments under first year defensive coordinator Justin Wilcox and his multiple-front schemes.
Some of the adjustments by the defense are also a direct result of the up-tempo offense run by Sarkisian in which the defense has to go against every day.
"I'm trying to play every snap at full speed," said Starr. "We go so fast at practice, you can't sprint to the ball every time because you have to be ready for the next play, but in games I just want to be able to play full speed, every play.
"Spring is going good. I'm just trying to work on scheme, get the technique down, get the playbook down – just trying to get better everyday."
Starr says he has high expectations for himself as he prepares to head into fall camp. His head coach echoes the same sentiment. "There's other guys who I think have performed well and I don't want them to fall off," Sarkisian said. "I'm thinking of Scott Starr, JR Tavai, Hayes Pullard… these guys have had great springs and I want them to finish this thing strong with great leadership so they can have command going into fall."