The former England under-21 international striker came off the bench to secure his side an FA Cup replay against Middlesbrough with his first goal after a frustrating 16 months
The former Manchester United and Hull City forward has been on the sidelines for an extended period after sustaining cruciate ligament damage in August 2010 but made a scoring return in the 1-1 draw with Middlesbrough on Sunday in the fourth round of the FA Cup.
And Campbell, speaking to BBC Newcastle, is optimistic that his injury troubles are firmly behind him.
"You can't let that creep into your mind or it'll affect your performance," he said.
"I didn't have the fear before I did it, so I've got to get back to that."
Campbell suffered a setback last April, when he was forced to undergo a second operation after a recurrence of the problem, and his return to action has been carefully managed by the medical staff at the Stadium of Light.
"You feel like you're ready to go, but we've got a great medical staff and a great coaching staff here," he continued.
"They don't want to rush me back, especially with the team doing so well. It's frustrating for me, but I know everybody's looking out for me."
And the 24-year-old also believes that his time away from the football pitch has only enhanced his love of the game
"I knew I loved football before but being out for so long makes you really appreciate what you've been missing" he added.