To get you ready for the 2016 NFL season, the PFF analysis crew is assembling team “cheat sheets” to catch you up on the latest changes, grades, and rankings of note involving your NFL team.

With quarterback Andrew Luck healthy and back under center following a career-low season, the Colts are hoping to reclaim the AFC South title from the Houston Texans. While Indianapolis made a key O-line upgrade at center with their first-round draft pick, key contributors such as Jerrell Freeman and Coby Fleener exited via free agency. Can the Colts rebound?

Three biggest things to know

1. The defensive back-seven is in trouble.

Earlier this summer, we highlighted the importance of Indianapolis' two starting cornerbacks, Vontae Davis and Patrick Robinson, playing up to the level they each did in 2015. Unfortunately, Davis has already suffered a sprained ankle that is expected to keep him out of action until at least October. The Colts acted quickly by signing free agent Antonio Cromartie, but if he plays anywhere near the level he did last season, the former Jet will prove to be a significant downgrade. Cromartie ranked 84th in our CB grades in 2015, surrendering five scores while only breaking up three passes; opposing QBs enjoyed a rating of 132.5 against him, the third-highest mark in the league. With the other back-seven starters slated to include rookie safety T.J. Green (who we were not high on throughout the draft process), ILB D’Qwell Jackson (who has graded toward the bottom of the league each of the past two seasons), and ILB Nate Irving (who has yet to reach 900 total defensive snaps for his five-year NFL career), it’s easy to understand why this group is likely to be a significant liability.

2. RB Frank Gore is being relied upon too much given his current skill-set and age.

Gore rushed for just 3.7 yards per carry last year and fumbled four times, the most for the former 49er since 2008. What’s more concerning is that the 33-year-old workhorse played a startling 707 snaps last season, third-most in the league at his position. He did manage to break 36 tackles last year (the seventh-highest total at the position), but in an era where so many teams utilize multiple backs to split reps in a variety of roles, Gore was simply overworked. Unfortunately, this does not look likely to change this season, as the new backup, free agent Robert Turbin, has been little more than a change-of-pace back during his four-year career, and is now on his fourth team in less than a year after playing just 154 snaps for the Browns and Cowboys in 2015 (he was given an injury settlement by Seattle early last September). With injuries so prevalent at the position, the Colts are not in a strong position at RB, and would do well to continue to test free agency or approach a team like the Giants, who appear to have a surplus at the position.

3. The Colts’ offense won’t improve just because Andrew Luck is healthy—he also needs to play better.

Andrew Luck struggled with injuries at various points of the season last year, finally being shut down after Week 9, but the fact of the matter is that he was playing terribly beyond whatever limitations his injuries were placing on him. Through nine weeks, he was last in PFF QB grades, last in adjusted completed percentage (which is completion percentage that takes into account drops, throwaways, and spikes), and second-worst in adjusted completed percentage under pressure. While adding rookie center Ryan Kelly will hopefully help to an extent, much will be on Luck to improve his accuracy and decision-making. He has shown prolonged flashes of brilliance throughout his young NFL career, but in year five, it's time for Luck to become the elite player the Colts are now paying him to be.

Key arrivals and departures

Top three draft picks: C Ryan Kelly (Round 1, pick No. 18 overall, Alabama), S T.J. Green (Round 2, pick No. 57, Clemson), OT Le'Raven Clark (Round 3, pick No 82 overall, Texas Tech)

Signed in free agency: CB Patrick Robinson (San Diego), RB Robert Turbin (Cowboys), CB Antonio Cromartie (Jets)

Left via free agency: ILB Jerrell Freeman (Bears), TE Coby Fleener (Saints)

Cut: WR Andre Johnson (Titans), C Khaled Holmes (Bears)

Retired: QB Matt Hasselbeck

Rookie to watch

Ryan Kelly, C, Alabama (Round 1, pick No. 18 overall)

Kelly is already plugged in as the day-one starter, and considering not just the position he plays, but the fact that he is the only new face on an offensive line that struggled last year, there will be a significant amount of pressure on him to perform. He developed into a solid run blocker while at Alabama, and through the 2014 and 2015 college seasons, did not yield a sack, surrendering just 13 total pressures (three of them coming in the national championship game against Clemson). He will need to show that same level of efficiency in Indianapolis in order for the Colts' offense to operate optimally, as they are at their best when QB Andrew Luck is able to make subtle adjustments while sliding up into a clean pocket—an opportunity he’s not consistently been given during his pro career.

Highest-graded player of 2015

Jack Mewhort, G, 85.5 overall grade in 2015

After bouncing between multiple positions throughout his rookie season, Mewhort finally settled into his most natural position at left guard starting in Week 2 of 2015, and finished the season with the ninth-highest grade at offensive guard. He was particularly adept at run blocking last year, with seven above-average grades to just one below-average (Week 15 against Houston). He still needs to significantly improve his pass blocking; although he did not yield a sack in 2015, he did give up 44 total pressures. Mewhort suffered a knee injury in Indianapolis’ third preseason game against Philadelphia, but luckily, what was expected to be a season-ending injury will not require surgery, and he'll likely reenter the lineup within the next month.

Breakout player to watch

Henry Anderson, DE

Anderson looked on his way to the Defensive Rookie of the Year award last season until a torn ACL against Denver in Week 9 prematurely ended his season. Already back practicing in full, the hope is that he’ll be able to recover quickly and pick up where he left off last season. Through the first eight weeks of the 2015 season, he had amassed 24 total pressures and 23 defensive stops, with only one missed tackle. Before the injury, he had the eighth-highest run-defense grade among 3-4 DEs, a remarkable feat for a rookie. If he can start to convert more of his pressures into hits and sacks (of his 24 pressures, only one was a sack and two were QB hits), he’ll quickly move into the league’s upper echelon at the position.

Projected lineups

Base defense (2015 season grades shown)

Offense with three receivers (2015 grades shown)