The Golden Wave's backup quarterback, a 6-foot-2, 172-pound junior, never thought he would play.
That all changed late in the game when starter Luke Hobson's fibula was cracked.
Harris, a quarterback since his days of playing pee wee football, was sent in with the seconds ticking down and Tupelo trailing. He threw two passes, the second an interception.
"It was shocking," Harris said of his experience. "When I got home that night, I knew football was about to take on a whole new meaning for me."
With Hobson sidelined for what could be the remainder of the season, Harris has been handed the offensive reins. In his first start - with plenty of help from running back Ashton Shumpert - he directed the Golden Wave to a 27-21 Division 1-6A win last week against Grenada.
Harris was 2 of 8 passing for 42 yards and threw an interception, but he survived the pressure of running a team.
"I thought he settled down in the second half and operated the offense the way we wanted him to," offensive coordinator Andy Crotwell said. "He threw some nice balls.
"He's getting more comfortable, playing within himself."
Harris has gone from being an afterthought at practice, to taking a majority of the snaps.
"I was nervous and anxious to take charge," he said. "I wasn't used to getting that many reps in practice. I was sweating. I was dog-tired."
In the first half against Grenada, Harris and Shumpert misfired on a couple of handoffs than led to fumbles.
"That was half timing and half nerves for me," Harris said. "In the second half, I stepped it up. The nerves disappeared and I felt more comfortable."
Crotwell doesn't expect the miscues in the backfield to continue. He cited Harris' first varsity start and Shumpert's second game back from a leg injury that caused him to miss four weeks.
"Hopefully, that's been ironed out," he said.
As for the two interceptions, the coach believes it was more of a lack-of-experience issue.
"He's used to playing JV ball where everybody plays man coverage or a simple zone," Crotwell said.
Tonight's foe, Southaven, rarely runs the same coverages two plays in a row. Harris hopes to be prepared.
"I just want to cut down on my turnovers," he said. "I want to lead the team a lot better. Hopefully, we can get another W."