It started festering in week one, when five Trojan running backs found the end zone against Virginia.
The sixth, redshirt freshman Broderick Green, rushed one time for no gain.
It continued like this for weeks, as Green struggled to break through the line of scrimmage for a significant gain. Eventually against Arizona State, Green started to make some plays, even rushing for 12 yards on one of his three carries.
Still, though, something wasn't quite right.
Saturday at Washington State, Green was likely going to get his chance. Injuries to Joe McKnight, Allen Bradford and Marc Tyler thrust Green up the depth chart the third.
"I was talking to my family and different players on my team and they kept telling me to keep my head up and stay focused," Green said. "They kept telling me my time would come. I guess this was my time."
After watching Stafon Johnson and C.J. Gable run all over Washington State's defense, Green finally got his chance.
Four carries in the first half yielded only six yards for Green — an average of 1.5 yards per carry. The other Trojans rushed for 7.8 yards per carry.
"The first time he came in, he was excited and anxious," running backs coach Todd McNair said. "He's the type of kid who can get a little out of whack."
Green struggled again to gain traction for most of the third quarter, and then, it happened.
"I was waiting on that run," Green said.
On the final play of the third quarter, the Trojans gave the ball to the big, powerful back, and in an instant, he showed everyone just what he could do.
Green got the ball and ran behind the right side of the offensive line. Green broke a tackle at the line of scrimmage and dashed for the end zone before being tackled on the one.
On the play following the 27-yard gain, Green scored his first collegiate touchdown.
"I was in the flow. I was focused," he said. "It felt like a huge weight was off my shoulders."
Green would go on to dominate in the fourth quarter, finishing the day with a game-high 121 yards and two scores.
After scoring, Green began to look like a different runner. He patiently cut back and found holes. He pushed the pile forward. He broke free, and in some ways, he broke out.
"It was good to see Broderick get his chance and get him rumbling," USC head coach Pete Carroll said. "You can see the kind of runner he is and the style that he has. It's an exciting style to add with the other guys we have. He brings it. He's good in the open field as well. He took care of the football really well.
"For the first time, he really had an extended opportunity, and he really answered it."
Teammates like Patrick Turner took notice of Green's performance, and after the Trojans' 69-0 win, he raved about USC's leading rusher for the day.
"It's really good to see guys like Broderick get in there and get a shot," Turner said. "It's even better to see him take care of business."
Green said superior blocking helped him break big runs and make big plays. He also said he left Martin Stadium feeling better about his game.
"It boosts my confidence a lot — big time. I'm ready to get more opportunities," Green said. "Hopefully, I showed the world what I can do, and I helped the team."
McNair said Green needed to have a good game and break some big runs before his desire to make a difference got to him.
"He's a super, super conscious kid," McNair said. "It was good to finally see him get to do his stuff. That was really good for him."
As he walked toward the Trojans' locker room, fans shouted praise his way. Media members flanked Green's broad shoulders, asking him about his day and how he felt.
Green flashed a huge smile.
"This right here," he said, "is the greatest feeling in the world."