Whittingham said he didn't handle the loss well and let it linger.
"It may have set the tone for a lot of things," he said.
The Utes lost five of their first seven games including the upset and finished 5-7 for their first losing season since going 5-6 in 2002, the last year Ron McBride served as coach.
Utah defensive end Trevor Reilly viewed the game as a possible two-win swing for the Utes.
"If we'd won that one, we would have gone to a bowl game and could have won that one," he said. "We would have had seven wins instead of 5-7, all because of Utah State."
Needless to say the Utes are hoping for some revenge come kickoff at 6 p.m. on Thursday.
The upset has renewed fire in a rivalry that is Utah's oldest with 111 meetings, but one that had staled in a way with Utah winning the last 12 prior to 2012.
Reilly, from Valley Center, Calif., admitted he didn't know much about the Aggies before coming to Utah other than possibly seeing them once on TV. Needless to say, his view has changed.
"For the rest of my life I'll look on them as a big deal," he said.
The upset might have been shocking, but it did offer a glimmer of what was to come for the Utes as the offense struggled that night and into the season.
This year, the Utes have a revamped and more confident offense that is eager to show it has improved.
Quarterback Travis Wilson, for one, has seven starts behind him and has benefited from a spring and fall camp of working with new co-offensive coordinator Dennis Erickson.
"Everyone is comfortable with the new offense," he said. "We've been running it spring and fall and everyone knows what we want to achieve, so I'm really confident."
Whittingham has made it clear he wants an offense that performs much better this season than a year ago when it averaged just 26.6 points.
He added more pressure last week when he noted the offense "had its butt kicked" by the Aggies.
Wilson knows the pressure is on, but said he is confident the Utes can deliver. After last year's upset, Wilson and the rest of the Utes know how important the game is.
"We have to come out strong and not come out flat," he said. "No one liked how the game ended last year, and we definitely want to come out and make a statement this year.
"We have to make a new memory this year," he added.