After being drafted by the Brisbane Lions as a first-round pick in the 2007 NAB AFL Draft, Henderson spent most of his two seasons at the Gabba playing in attack.
But after joining the Blues as part of the Brendan Fevola trade at the end of 2009, he has played almost exclusively as a key defender.
Henderson told SEN radio on Monday morning playing in defence had given him the confidence he belonged in the AFL.
"If you'd asked me last year I might have still said (I'd prefer playing) forward," he said.
"I actually am enjoying playing back. It's been really good for me. It's given me that confidence to play footy and I'm really enjoying it."
However, despite his impressive recent development, Henderson conceded he was still learning on the job as a key defender.
"I'd love to say I had it nailed. I'm going all right. I'm still learning. I'm still really working at it," he said.
"But I'm definitely a lot more comfortable down there than I have been and I've got a lot more confidence down there."
Henderson said a key factor in his growing confidence was developing the belief that he could fight back if an opponent was on top of him early in a game.
"I finally found that little bit of confidence where I backed my ability in against most people," he said.
"It is tough at times when you get beaten early. I think last year in the finals (Essendon's Michael) Hurley beat me a couple of times straight out in the first quarter.
"And just to fight back from that was good. It was good also having 'Jamo' (Michael Jamison) there where we could just swap and change and work through it that way."
Henderson credited much of his development as a defender to his work with Jamison and Blues assistant coach Gavin Brown.
Nick Bowen is a reporter for AFL Media. Follow him at Twitter @AFL_Nick
