One area that is getting a makeover is safety, where first-round draft pick Malik Hooker is expected to push for a starting job.
Hooker, though, will not participate in OTA work and his availability for the start of training camp is in question after the former Ohio State standout underwent surgery in January for hip and sports hernia issues.
It's hoped that he will be able to return for the early stages of training camp, which begins the last week of July.
Third-year safety Clayton Geathers is also missing OTA workouts after undergoing surgery in March to address a bulging disk. Geathers had a foot injury heading into last season and then was sidelined late in the year with concussion symptoms.
He was later diagnosed with the disk problem after experiencing pain. According to both head coach Chuck Pagano and Geathers, the decision to undergo surgery was "the last option."
"Clayton was hurt on the final play of the Tennessee game (on Nov. 20). He had a concussion and then developed further symptoms," Pagano explained Tuesday.
Geathers was placed on injured reserve for the remainder of the year at that point. That's when the disk injury was discovered.
"Surgery was the last option," Pagano explained. "He's rehabbing and he's right on schedule."
So is there a timetable for when Geathers is expected to return to the practice field? Not just yet.
"When I'm ready, I'm ready," the former Central Florida defensive back admitted. "The surgery was a success. I've been getting positive notes from the doctors.
"I trust the process, trust the surgery. I know my style of play. And once (the disk) heals, I'm ready to go. We'll see how it goes."
The decision to have the surgery was reached after consulting with the Colts' training and medical staffs, as well with his family. He then met with multiple doctors in order to come up with a plan to address the issue.
"The surgery has been a success," Geathers said. "It's looking good, starting to do more movement."
With Hooker and Geathers both sidelined, former cornerback Darius Butler will continue to see work at safety. Butler has been playing cornerback, but slid over to safety last season due to injuries at the position. He's fully on board with the move.
"I'm practicing (at safety) until I'm told otherwise," he said.
Second-year safety T.J. Green is also getting additional reps during the OTA workouts.
Defensive coordinator Ted Monachino says putting the best group of five defensive backs on the field to begin the 2017 season is the key.
"What will happen is those best five guys will be out there in nickel. And if Darius isn't the nickel corner, then if he's one of those best five he'll be playing the deeper parts of the field. He's pumped up about whatever role," Monachino said.
"He knows and we all know what a blessing and an opportunity it is to be in an NFL building. He's just thrilled to be back and can't wait to get started carving out a new niche and a new role because from a leadership standpoint, that spotlight has become brighter with Darius."