SPARTANBURG, S.C. -- Shortly after Muhsin Muhammad re-signed with the Carolina Panthers, he saw Dwayne Jarrett catch a pass during a workout and lightly jog up the field.

It didn't take long for Muhammad to pounce, leading to another painful lesson for the second-year receiver.

"I told him that the one thing you don't have to coach is effort," Muhammad said Wednesday. "When you catch the ball, get up the field. Give me 10 yards. I'm going to do it every single time I catch the ball, I'm going to sprint up the field for 10 yards. I want you do the same. Give me some effort. That's all I'm asking just to start off. Those are the little things that make you a professional."

Becoming a professional has been difficult for the 6-foot-4 Jarrett, who set the Pac-10 career record with 41 touchdown catches in only three seasons at Southern California. The Panthers felt so highly of their second-round pick last year that they released Keyshawn Johnson three days later.

But not only did Jarrett not replace Johnson as the big, possession receiver next to Steve Smith, he couldn't get a jersey on Sundays. Slow to learn the playbook, Jarrett spent much of the first half of the season on the inactive list.

Then came the embarrassing locker-room incident when Smith interrupted Jarrett's interview with reporters, telling him he should go watch film.

Jarrett finished with only six catches for 73 yards and no touchdowns, and capped his disastrous 12 months by getting arrested on a drunk driving charge in March.

"It was something I learned from," Jarrett said of pleading guilty and being sentenced to 24 hours of community service. "It'll never happen again. It's just a part of growing up and being responsible and making the right decisions."

The 35-year-old Muhammad has made Jarrett, who doesn't turn 22 until September, his project in camp. Not only are they both tall, possession receivers, Muhammad also had legal troubles early in his career involving possession of marijuana and guns.

"You have to be able to admit that you were wrong for what you did, put it behind you and not make the same mistakes. That's basically what I told him. Move on," Muhammad said. "You have to be able to move on. And you have to win trust back. You have to win your fans' trust, your coach's trust and ownership's trust."

On the field, Jarrett has looked sharper running routes and shown good hands while working with the second team in training-camp practices.

"Some people questioned what he knew playbook-wise, but from what I've seen he's hitting the books a little harder," Muhammad said.

Jarrett, who insists he's patched things up with Smith, acknowledged Wednesday that the transition to the NFL has been more difficult than he thought. But he believes he now knows what it takes to succeed.

"I think it's just more an understanding of the game and being more of a student," said Jarrett, who set school records with 216 catches for 3,138 yards at USC. Just really buckling down as far as playbooks and learning the details of the game. I learned doing that just helps me so much out there on the field. It's like night and day."

But Jarrett faces increased competition to move up the depth chart. The ineffective Keary Colbert and Drew Carter were not re-signed in the offseason and were replaced by veterans Muhammad and D.J. Hackett. They have worked as the second and third receivers after Smith.

Ryne Robinson, who returns punts and kickoffs, is fighting for the No. 4 receiving job with Jarrett. The two have worked together for much of camp.

"He's not the same Dwayne as he was last year. It's evident to everybody," Robinson said. "He has a different attitude, not being so comfortable with everything. He's coming out and actually working at it."

Jarrett knows he needs to keep that increased work ethic to erase memories of a miserable 2007.

"Just the whole NFL experience of being a rookie, I grew from that last year," Jarrett said. "Definitely coming into camp, I've proven that I've gotten over my humps and I've turned that corner."