How good can the Colts be with healthy Luck in 2018?

Indianapolis Colts quarterback Andrew Luck took a major step on his road to recovery Tuesday after undergoing shoulder surgery in 2017 - he was spotted throwing at practice for the first time since October.

The former No. 1 overall pick still has a long way to go before suiting up in a regular-season contest, but the recent news will have NFL fans excited at the prospect of the premier quarterback returning to the field.

But just how good can Indianapolis be with Luck upon his return? Here's a look at key Colts stats with and without their star quarterback since he was drafted in 2012:

There are times where numbers do not tell the entire story, but this isn't one of those instances. The numbers speak for themselves: since entering the league, Luck has perennially made the most of a subpar Colts roster, winning two division titles and leading his 2014 squad to the AFC Championship game with a below-average defense, and with a rushing attack featuring Trent Richardson and Dan Herron.

Luck's return will allow Indianapolis to compete in the AFC under new head coach Frank Reich. When healthy, the Stanford alum is a top-tier quarterback. His best completions leave fans and evaluators in awe, as there aren't many signal-callers that can sling it like Luck. Arm strength, poise, accuracy, high football IQ, timing - he has it all.

Improved roster

Ryan Grigson, the Colts general manager who many have faulted for the team's lack of success during his tenure, was fired after the 2016 season. His replacement, Chris Ballard, has attempted to rectify Grigson's biggest blunders. The result is a more balanced roster than Indianapolis fielded in 2016 and 2017.

Ballard's emphasis on bolstering his offensive and defensive lines are at the center of this improvement. The Colts drafted Quenton Nelson and Braden Smith in the first and second round, respectively, and both rookies could start immediately (Nelson is all but locked in at left guard). Add the two youngsters to dependable left tackle Anthony Castonzo and 2016 first-rounder Ryan Kelly at center (if healthy), and Ballard's squad will feature its best blocking unit in years. This, of course, will benefit their quarterback more the anyone. Luck was sacked 41 times in 2016, and was pressured on 44.4 percent of his dropbacks, per Pro Football Focus - the highest rate in the NFL.

Related: Andrew Luck: 'Absolutely,' I will play Week 1

On the defensive line, Jabaal Sheard had an excellent first season in Indianapolis, and is an ideal fit in Matt Eberflus' new 4-3 scheme. Since Ballard was hired, the Colts also selected Tarell Basham, Kemoko Turay, and Tyquan Lewis on the draft's second day. Ranking 31st in 2017 with only 25 sacks, Indianapolis' pass-rush should improve in 2018.

While the Colts still have weak spots on their roster, specifically at wide receiver, linebacker, and cornerback, there are promising young players ready to step up. Tight ends Jack Doyle and Eric Ebron, the latter recently signed after being released by the Detroit Lions, should help lighten the load for Luck's inexperienced receiving corps.

Competitive division, weak conference

(Photo courtesy: Action Images)

The AFC South is no longer the conference's laughing stock, and there are opportunities for any of its four teams to hoist the crown. The Jacksonville Jaguars will be favored, but can their defense maintain its historic pace and negate subpar quarterback play? The Tennessee Titans will field a new offensive and defensive scheme in 2018, so there could be growing pains. Finally, the Houston Texans have the greatest upside, but quarterback Deshaun Watson is no sure bet to return to pre-injury form, especially early on. It's important to note that with Luck, the Colts have a distinct advantage over the rest of the division where it matters most - at quarterback.

Perhaps Indianapolis' best bet for a playoff berth in 2018 lies in a wild-card spot. The AFC is nowhere near as competitive as the NFC. Outside of the New England Patriots and Pittsburgh Steelers, the conference is wide open. The Titans and Buffalo Bills both made the playoffs at 9-7 last season.

The verdict

Luck is undoubtedly the Colts' biggest question mark heading into the 2018 season, but his reinsertion into the lineup will provide his team with a massive boost. If fully healthy, Luck is one of the most talented passers in the game, and will lead an improved roster in a wide-open AFC South. Much like an elite point guard in basketball, the veteran signal-caller makes everyone around him better, and has been successful with lesser talent in previous years.

A division crown could be an unrealistic expectation, but Indianapolis could absolutely earn a playoff berth, their first since 2014, with Captain Luck at the helm.