He's still here, and he's not planning on going away. In fact, Harrison's playing pretty well and is pushing for either the fourth outside backer position or a brand new fifth spot replete with special-teams duties.
"My father always told me," Harrison said, "that there are two things in life you never waste: time and opportunity, because you never get either one of them back."
So Harrison is making the most of it. In the final edition of the popular camp blitz drill called backs-on-backers, the 6-3, 241-pound Harrison blew up 6-6, 260-pound rookie tight end Charles Davis.
Harrison not only ran Davis over, he knocked off his helmet and popped a contact from Davis's eye. On his next rep, Harrison took a different approach: He gave Fast Willie Parker a ghost move and glided past him and into the quarterback's face. It was a move Parker might use on a linebacker in the open field, so Harrison gave Parker a taste of his own medicine.
"Show power; show speed; show something," Harrison said of his intentions.
Harrison played well on special teams last Saturday in the preseason opener. With all eyes on potential wedge-buster Lee Vickers, it was instead Harrison who stood out.
"He showed up pretty good last week," said special-teams coach Kevin Spencer. "He covered kicks well, ran well. He can run now, so he showed up. I mean, it was one of those games where nobody was really lights out, but out of everybody he showed up. He did a nice job. He can run. That's the key."
It's becoming obvious that the kid who keeps hanging around is beginning to play some good football.
"I'm just working," he said. "It's a blessing to be out here. Playing for the world champs, man, in the best linebacking corps in the NFL, you can't ask for much more. I'm blessed."
Harrison might be part of "the best linebacking corps in the NFL," but he's not even the best Harrison at his specific position. Super sub James Harrison is the second-team right OLB behind Joey Porter (as well as left OLB Clark Haggans) and Arnold Harrison is third team. So is Arnold Harrison the forgotten Harrison of the two?
"I wouldn't say I'm the forgotten Harrison," he said. "James Harrison deserves any accolades that he gets. He worked hard for a long period of time to get where he is. He and I were roommates in camp last year and I learned a lot from him and I'm trying to follow in his footsteps. He taught me to keep fighting because it will give you an opportunity for good things to happen."
How do the coaches make sure they get the right Harrison's attention?
"They call me Arnold or Snelling," he said. "And they call him Silverback."
"I made up a song about Snelling Dining Hall back in Georgia and I sang it on Rookie Day last year, so everyone started call me Snelling."
Harrison signed with the Pittsburgh Steelers as an undrafted free agent out of the University of Georgia in 2005. A shoulder injury plagued his senior season after starting 10 games as a junior. His best game was the 2003 SEC Championship Game in which he made eight tackles against LSU.
A native of Augusta, Georgia, Harrison, of course, enjoys golf in his spare time, or when he's not blowing up tight ends in practice.
"Aw, man, it's a physical sport," he said almost apologetically about his hit on Davis. "It's a sport built for men, so we have to get after each other. Hey, he's trying to do the same thing to me."
To blow up or be blown up; that is Arnold Harrison's question. And we saw his answer.