If he keeps doing what he's been doing when Miami visits Memorial Stadium on Saturday night, no one will doubt the strides Armstrong has made since he was forced into the starter's role a year ago.
Armstrong has had more than 300 yards of total offense in each of Nebraska's three games, and he's thrown seven touchdown passes against one interception. All that was accomplished, however, against statistically the worst and second-to-worst defenses in the Bowl Subdivision and an opponent from the second-tier Championship Subdivision.
The No. 24 Cornhuskers (3-0) are fifth nationally in total offense, averaging 594 yards a game and 8 per play. The Hurricanes (2-1) are eighth in total defense, allowing 259 yards a game and 3.7 per play.
"It's plain and simple: we know it, and our coaches know, when we prepare the right way, we know defenses better than they know themselves," Armstrong said Monday. "I don't think anybody can stop us."
Armstrong is throwing for almost 260 yards a game as the leader of Nebraska's self-titled "Red Storm" offense, but his completion rate of 53 percent is virtually unchanged from a year ago. His one interception in 81 attempts is markedly better than last year, when his eight picks on 131 attempts was the fourth-worst ratio in the country.
The biggest change in his game has come as a runner. He's averaging 86 yards a game, sixth-best among quarterbacks, and 9.6 a carry, seventh among all rushers.
Armstrong, whose 258 rushing yards already exceeds his 13-game total in 2013, has benefited from defenses stacking the box to keep star running back Ameer Abdullah under control.
"We need Tommy to definitely be someone who can counter that, someone who can pull the ball (on zone reads) and be an effective runner," Abdullah said. "He's a great runner. This is just the beginning. There's more to come."
Coach Bo Pelini said Armstrong has to be cautious, though. He tried to hurdle defenders on a couple runs against Fresno State, landing on his right (throwing) shoulder on one of the plays. Armstrong said the coaches have warned him about putting his body at risk, but it's his nature to be physical.
"I want to make sure I make a statement, make sure I get hard yardage just like the running backs," he said.
Abdullah said Armstrong's increased confidence is the most noticeable change he's seen in Armstrong. Armstrong had played sparingly before taking over for an injured Taylor Martinez after the third game last season.
"It's going to be a good challenge for him," Pelini said. "It's not like this is Tommy's first rodeo. He started in eight football games a year ago. He's basically played, and when you add the three games he started this year, he basically has played a season now. His experience helps him. I think he's getting more comfortable as he goes."