INDIANAPOLIS — So what all did we learn the past couple months about the Indianapolis Colts?

In an offseason chock-full of changes — particularly with a new head coach and a new face at just about every spot on the coaching staff — that list, in its entirety, would be pretty lengthy.

Fortunately, we're here to lighten that load and provide the most noteworthy takeaways from the Colts' offseason workout program, which kicked off with Phase 1 on April 9, and concluded on Thursday with the third and final day of mandatory minicamp practices:

• A new leader:
The Colts in February hired Frank Reich to be their next head coach, and by the end of the month, he had assembled a diverse coaching staff, which consisted mostly of newcomers to the organization.

By the time offseason workouts began in April, we knew Reich and his offensive coordinator, Nick Sirianni, would be leading the charge for a new-look offensive attack; one that features a lot more energy and pace than previously seen in Indy. New defensive coordinator Matt Eberflus, meanwhile, had started the process of transitioning the Colts’ defense from a 3-4 to a 4-3 base scheme, with an emphasis on speed and effort.

And what was the result by the time the offseason program had concluded? Reich said both offensive and defensive staffs accomplished their goals of not only establishing expectations and beginning to define roles, but they also were able to install about 75 percent of their respective playbooks heading into the start of training camp next month.

"I think we've accomplished what we wanted to accomplish in a couple areas – playbook, scheme, body composition, getting in shape and then come together at some level," Reich told reporters on Thursday. "It's still growing, but it was a really good start."

• Andrew Luck takes positive steps:​
A couple weeks before the offseason program got started, we learned quarterback Andrew Luck had introduced smaller footballs into his workouts as he continues rehabbing his surgically-repaired right shoulder.

And by the time last week's mandatory minicamp had ended, Luck had introduced a regulation-sized NFL ball into his workouts, and was extremely optimistic about his chances to both be ready for a full practice workload by the time training camp started, as well as his availability for the Colts' regular-season opener against the Cincinnati Bengals.

The ability to methodically cross every step off the list — no matter how big or small — has been a huge boost for Luck this offseason; now Reich says he has four key throwing goals to work on this offseason heading into training camp.

"You go from where you're throwing pretty stationary, not a whole lot of movement," Reich said. "Then some of your movement throws; then you're spotting receivers up and you're throwing to spots; and then the next step after that is throwing competitive throws to receivers who are running full speed. We certainly would need to work to get that in before the return (to training camp).

Luck has also established a new weekly throwing routine; one that more closely resembles his workload during the regular season. He'll throw a certain number of passes on what could be considered a Wednesday, Thursday and Friday of a game week, rest on Saturday, and then let it fly on Sundays, like he would during a game, all to get his body adjusted to that schedule by the time training camp hits.

"So that's what I'm preparing for, that's why right now I throw Mondays, Tuesdays and Wednesdays and Fridays to mimic a three-day sort of practice week and then a Friday as a Sunday as a game week," Luck said on Tuesday. "That's the sort of big picture I'm preparing for and the goal certainly, more short term, is to be ready to go for training camp. To be able to not just participate, but get better, get the team better. Go and see what we can make this year's Colts."

• Draft class learning ropes:​
Just prior to the start of the offseason workout program, general manager Chris Ballard brought in a Colts modern draft era-record 11-player 2018 NFL Draft class.

While the team used the sixth-overall pick on guard Quenton Nelson out of Notre Dame — considered by many experts to be a can't miss prospect along the offensive line — Ballard would add talent and depth across the roster with the rest of his picks, too. In all, he selected two offensive linemen, two defensive linemen, two running backs, two wide receivers and three linebackers.

Some players — Nelson, defensive tackle/defensive end Tyquan Lewis, running backs Nyheim Hines and Jordan Wilkins, wide receivers Reece Fountain and Deon Cain and linebacker Zaire Franklin — were seen getting significant reps at some point during offseason practices with what could be considered the "first-team" offense or defense.

Others — guard Braden Smith, defensive end Kemoko Turay and linebacker Matthew Adams — might've had some first-team reps sprinkled in here and there, but for the most part have been key pieces of depth for two fast-moving Colts units that will count on having fresh players ready to go at a moment's notice during the season.

But apparent injuries have also limited several members of the Colts' 2018 draft class from participating in much of the on-field portion of the offseason workout program, a list that includes linebacker Darius Leonard, Turay, Lewis and Hines, all of whom were either limited or out at various practice sessions available to be viewed by the media (the team isn't obligated to provide an injury report during the offseason).

While several rookies or otherwise younger players are expected to play major roles for the Colts in 2018, the team is hoping to see every one of these aforementioned players on the field at the start of training camp so they can play catch-up to the rest of their teammates.

• Other injury updates, concerns:​
Beyond the Colts' 2018 draft class, the team has several other players coming back from or battling injuries that they hope will be cleared up by camp.

What we know: running back Robert Turbin (elbow), cornerback Pierre Desir (pectoral), guard Jack Mewhort (knee) and guard Matt Slauson (biceps) all seemed to be full-go during most of the offseason workout program after suffering season-ending injuries the year prior. That's the good news.

On the other end of the spectrum, however, several Colts players were either limited or unable to participate in the offseason program, including safety Malik Hooker (knee), running back Marlon Mack (shoulder) and center Deyshawn Bond (quad), while many others were out due to undisclosed possible injury issues: safety Ronald Martin, cornerback D.J. White, safety Clayton Geathers, guard Jeremy Vujnovich, wide receiver Chester Rogers and tight end Erik Swoope.

Linebacker Anthony Walker, meanwhile, suffered a concussion during the second mandatory minicamp practice last week and, according to Reich, is in the league's concussion protocol. Also, defensive end Chris McCain missed last week's minicamp as he continues addressing an ongoing legal issue.