Luck ranks 10th among all NFL rookies (including running backs) with 159 yards on 34 carries -- five of those for touchdowns. The quarterback's decision-making about when to take off with the ball has been impressive. Half of those runs have generated first downs.
"His athleticism puts himself in harm's way a lot," Arians told Mike Chappell of The Indianapolis Star. "You've got to be able to protect yourself out there and get rid of the football at times and other times just be tough enough to handle it. I'm not going to change a bit the way he plays or approaches the game because other guys get concussions."
Luck's ability to extend plays is akin to what makes Ben Roethlisberger so dangerous with the Pittsburgh Steelers. They're not the same guy, but Big Ben has rescued the Steelers' offense from countless jams by knowing when to take off with the football. Before Arians coached Luck, he guided Roethlisberger to two Super Bowl titles.
"Part of playing the position is extending the play," Luck said, "and I've always felt comfortable throwing on the run. Even at a young age in high school, I was always begging the coaches, 'Make one of the first passes a bootleg.' I like getting into a rhythm that way."