"I was really nervous, because being from Pennsylvania and going back to my hometown state to start, I had family and friends that I knew were going to come. And with Marshall not being able to play that day, I just wanted to make sure I didn't mess anything up," Harris laughed.
"Marshall helped me with knowledge of the game and comforted me, calmed me down. Also, (running backs coach) Wilbert Montgomery. Again, being from Pennsylvania, I looked up to him, I knew who he was as an Eagle. So those guys really rallied around me.
"And not just even in the running backs room. The line, (Adam) Timmerman, (Orlando) Pace, and (the quarterback) Marc Bulger, those guys really made me feel comfortable going into that game. So I felt prepared."
To be prepared. Any Boy Scout who wasn't waving a Terrible Towel would have been proud of Harris' performance on Heinz Field that afternoon.
Aside from Bulger keeping the ball three times and gaining 8 yards, Harris was the only Ram to run the ball, finishing with a game-high 34 carries for an also game-high 81 yards and three touchdowns in the 33-21 victory.
"It wasn't the best weather," Harris said. "I had over 100 yards in the first half, and then ended up losing yards because we just wanted to run the clock out. Coach (Mike) Martz said, 'I don't care, just protect the football. Get a yard or two and let's get out of here.' And that's what we did. I mean, that was the most carries I ever had at any level.
"It was insane. And that defense was like No. 1 at the time. So if you add every type of stress that you probably could in your first start, I had it."
A Ram for three seasons before finishing his career in Detroit in 2006, what are among Harris' fondest memories from his time with St. Louis?
"I would say being able to win our division (in 2003)," he said. "And it kills me to this day. If (Carolina's) Steve Smith doesn't catch that ball (in the second OT of the divisional playoff game to win, 29-23), I think we go to the Super Bowl.
"That whole rookie year was like a movie where everything played out, being able to win the championship in your division. And as much as I played, and being able to play with the guys around me, it was… Yeah, it was priceless."