To understand how much Andrew Luck means to the Indianapolis Colts, you have to have a sense of the degree to which he's made up for all that has followed his arrival in Indianapolis. The top quarterback in the celebrated 2012 draft class, Luck quickly lifted the Colts to heights they probably shouldn't have reached so soon after the departure of No. 18, especially considering their missteps after hitting the lottery in getting him.

The Colts' situation drives home the point: In a league in which the passing game is king, it has never been more important to have a top-tier player at the sport's most important position.

In fact, Luck has been so effective at plugging holes, the Colts have a real shot to end up in the Super Bowl this season. He's just that good. No one needs to tell Mike Shanahan.

The former longtime head coach, who tutored Hall of Famers John Elway and Steve Young, among other signal-callers, studied Luck closely prior to his rookie season when the Redskins were maneuvering for their own franchise QB, and continues to monitor the Pro Bowler's career. Elway and Young were great, "but for me, this guy [Luck] changes everything," Shanahan said on the phone this week. "What he does, and there are very few guys like this [in NFL history], is that he can get the most out of people.

"He really makes the people around him better. I'm not just talking about the offense, I'm talking about your whole football team, because of all the things he can do. He has so much physical ability, yeah. There's no question about that. But it's also his mindset and the way he handles himself. ... You know your football team isn't going to be perfect; never is. But he's so smart and has such unique skills, he can really cover up a lot."

The Colts have needed many patches.

Even though the running game has been de-emphasized in the NFL, the Colts have been about as successful on the ground as the Redskins are at public relations. Stability along the offensive line, to put it kindly, has eluded Indianapolis. And although the team's defense has trended in the right direction during Luck's first three seasons, the Luck-led offense has done a disproportionate amount of the heavy lifting.

How is it that the Colts, despite their shortcomings, have reeled off three consecutive 11-5 seasons, won two AFC South titles and advanced further in the playoffs each year, finishing a step short of the Super Bowl in 2014? One word: Luck. General Manager Ryan Grigson has needed him the most.

Tasked with rebuilding the Colts' roster after they made the transition from Peyton Manning to Luck, Grigson, who cut his teeth rising through the scouting ranks with the St. Louis Rams and Philadelphia Eagles, got off to a smashing start: He won executive of the year as the Colts rebounded from a 2-14 mess in 2011 to return to the playoffs the following season. Of course, you don't have to be a player personnel savant to realize that using a No. 1 overall selection on Luck, arguably the greatest quarterback prospect in a generation (who had more potential than Elway in 1983?), would provide a fabulous foundation for the future.

Since making that no-brainer move, though, Grigson hasn't exactly had a golden touch. Trading for Trent Richardson was his worst decision. In September of 2013, Grigson acquired Richardson, who was widely considered the best running back prospect in the 2012 draft, from the Cleveland Browns for a first-round pick. Grigson envisioned a dynamic pass-run tandem that could power Indianapolis for a decade.

A bad fit from the start, Richardson was released in March. In 29 games, Richardson gained only 977 yards on 316 carries (a 3.1-yard average), which was far less than what Grigson expected after surrendering the Colts' 2014 first-round pick for the third overall pick in '12. Richardson also was suspended during the playoffs last season. No general manager is perfect. Moves that appear spectacular on paper often play out horribly on the field. Clearly, for the Colts, that's what happened with Richardson. But here's the problem: During an era in which backs have been greatly devalued, Grigson wasted a huge value slot on a player who, as a rookie, was slowed by injuries and ineffective. There were better ways to help Luck.

Andrew Luck will miss Week 4 with a shoulder injury. Luck has been blitzed and pressured more than ever before this season. AP Photo/Michael Conroy

Relying on the running game and playing stout defense is straight from the how-teams-can-best-support-young-quarterbacks playbook. The Seattle Seahawks have utilized the proven formula to help Russell Wilson, another 2012 draftee, become a Super Bowl-winning rock star. Luck doesn't need to be propped up as much as Wilson. That Grigson hasn't acquired a serviceable back, however, is a bad mark on his record.

No Colts back has rushed for at least 100 yards in the past 48 regular-season games. Including the postseason, the drought stands at 54 games. Then there's the offensive line. In 16 games last season, Indianapolis had 11 different O-line combinations.

As for the Colts' defense, it has ranked 26th, 20th and 11th, respectively. As evidenced by the 45 points the New England Patriots scored in winning last season's AFC title game, the Colts still have a lot of work to do on that side of the ball, which brings me to Bjoern Werner.

Grigson used the 24th overall pick in the 2013 draft to select the outside linebacker from Florida State, hoping he would grow into a dominant edge rusher. With Dwight Freeney and Robert Mathis, the Colts had been set for years in that area, but Freeney moved on after the 2012 season and Mathis, who led the league with a personal-best 19.5 sacks in '13, missed all of last season because of an Achilles injury. Werner failed to step up.

He produced only four sacks in 15 starts, putting his two-year total at a paltry 6.5 sacks and one forced fumble in 28 games. Werner lacks elite pass-rushing moves, said a former NFC defensive coordinator who has studied tape of the Colts, and doesn't use his hands well enough to overcome his "average" athleticism. It's not surprising Werner was inactive for last season's AFC title game despite being healthy. It may be a tad too early to label Werner as a draft bust -- but it's getting close.

For Grigson, that's why it's good he also drafted "Michael Jordan." Grigson has compared Luck favorably to the basketball legend, who is generally regarded as the greatest player in NBA history. In ESPN's 2015 NFL QB Tier Rankings, Luck finished third behind Aaron Rodgers and Tom Brady. Luck, though, was by far the youngest quarterback in the top tier: He turns 26 on Saturday. That's why some around the league believe Luck could wind up becoming the greatest passer in NFL history.

Count on it, Shanahan says.

"Let me put it this way: Luck will be the best player at the quarterback position to play the game," the two-time Super Bowl winner said. "I think back to when I was [evaluating Luck] before the draft. We went out to Stanford [when Shanahan was with the Redskins] to watch him work out and he blew me away. There were some questions about his arm strength. We go to the field, he took a half step, not even a full step, and he threw the ball 80 yards in the air. It was like coming out of a ... Jugs machine.

"Now don't get me wrong. I've worked with some great, great quarterbacks. And I'm very high on Peyton Manning. I'm very high on Aaron Rodgers. There are other great guys. But Luck ... he's a freak of nature. He's [240] pounds and can move. He has all of that, and he's also a guy who develops relationships with the people around him. Football is very important to him, but his relationships are even more important to him. Like I said, he changes everything."

There's no doubt about it. While enabling Indianapolis to overcome Grigson's head-scratchers, Luck has become the face of the NFL. The Colts have the right person at the front of the line -- and they'll be able to follow him for a long, long time, seemingly regardless of what kind of roster-building takes place around him.