The Indianapolis Colts struggled to an extreme degree last season. And while you can point to a lot of trouble spots that GM Ryan Grigson failed to adequately address - the offensive line, running back depth, talent at nearly every level of the defense - there was really one reason the Colts failed to reach the postseason for the first time since drafting Andrew Luck in the first-round of the 2012 NFL Draft - Luck.

Almost from the outset, Luck didn't seem himself. And while he attempted to tough out whatever was ailing him - an injury that was likely the product of a mediocre Colts run game and a lack of adequate blocking - Luck eventually missed nine games of the 2015 NFL season and played relatively poorly in the other seven.

Going forward, Colts head coach Chuck Pagano probably knows he needs further reinforcements at those troubles spots in order to keep Luck upright and playing, but he also thinks that Indianapolis' franchise quarterback needs to do a better job of protecting himself with his playing style.

"Get him healthy, keep him healthy, keep him protected, keep him upright," Pagano said recently. "He plays the position like a linebacker, with a linebacker's mentality. He can't do that all the time. We love how he can extend plays, but he's got to be smart and know it's OK to slide. You don't have to take some of those hits."

One of the hallmarks of Luck's play through the first four seasons of his NFL career has been his ability to stay on his feet, absorb hits and keep his eyes down the field. His ability to extend plays with his feet, the product of his impressive athleticism, was one of the biggest reasons Luck went first overall in 2012.

But it's a tendency that nearly every other franchise quarterback in the league, even the most athletic ones, have eventually learned to weed out of their game, utilizing it only when absolutely necessary. From Ben Roethlisberger to Aaron Rodgers, to Matthew Stafford and Alex Smith, many of the league's starting signal-callers have found longevity through avoiding contact and saving athletic plays for when they need it the most.

Lucky, 26, is still in the development stage of his career. He looked to have taken a major step forward in 2014 when he tossed 40 touchdowns and just 16 interceptions, though he also ran the ball 64 times, a career-high.

Last year, in those seven games, Luck had run the ball 33 times for 196 yards. Now, because of the lackluster Colts running game and the mediocrity of the blocking in front of him, it's not surprising that Luck was forced to break the pocket and run more often.

But if there's a way to ensure that Luck stays healthy and on the field going forward, it's going to come down to Grigson adding talent to the Indy blocking and running game, and Luck making more of a conscious effort to protect himself.