Since the new league year started on March 9, the Colts have lost three starters and added one backup. Though their moves (or lack thereof) are not unexpected, they do open up holes and question marks on the roster: namely in the role of three "starting" spots that have now opened up. What will the Colts do to fill them?
Of the three players that the Indianapolis Colts have lost in free agency, the biggest one is undoubtedly the loss of inside linebacker Jerrell Freeman. That's not as much because of Freeman himself - though he is certainly a good player - as it is because of the options behind him. Though the Colts lost safety Dwight Lowery, they have Clayton Geathers waiting in line to step in. Though the Colts lost tight end Coby Fleener, they have Dwayne Allen and (likely) Jack Doyle to take the spot. But who is there to fill in for Freeman?
For the past four years, Jerrell Freeman has been the Colts' starting inside linebacker, and he has been a productive one at that. Over the past two seasons, he has played alongside D'Qwell Jackson, and there has really been no competition whatsoever for those linebacker spots. Last offseason, though, the Colts did sign free agent Nate Irving, and interestingly it was a three-year deal worth $7.25 million. He has a $2.5 million cap hit in 2016 and a $3 million cap hit in 2017, so the Colts obviously liked Irving last offseason. Unfortunately, much of his first year with the Colts was spent rehabbing a knee injury, and that led to him playing in eight games. He did start two of them, though, as he was the option to replace Freeman when the linebacker missed some time. He recorded 14 tackles, a sack, a forced fumble, and two passes defensed during his action with the Colts. He does have some experience, as in his five-year career he has made 14 starts and has played 62 games. He is the most likely option to replace Freeman, though he's still not a great one.
Another option would be Sio Moore, who the Colts acquired in a trade with the Raiders last year, but this one seems much more unlikely than Irving because the Colts didn't use Moore a ton last year anyway, opting instead for Irving or even Amarlo Herrera. Herrera too would be an option, though not nearly as likely as Irving. The rookie last year spent time back and forth between the active roster and the practice squad, and while Herrera and Moore would likely both be given the opportunity to compete, they likely wouldn't beat out Irving for the spot.
Besides for Nate Irving, the most likely option to replace Jerrell Freeman is a rookie, as the Colts could draft someone to fill the spot - they've shown some interest in Alabama inside linebacker Reggie Ragland, for example. So it's probable that the team will have either Nate Irving or a rookie starting at inside linebacker next season alongside D'Qwell Jackson, furthering the belief that they don't really have a great option that inspires confidence. Further complicating things is the fact that Jackson will turn 33 years old during the 2016 season, and the Colts need to be thinking long-term to the reality that they will have to replace Jackson before long, too. So while they may have a decent option to replace Freeman this year, they will soon have to replace their other starter as well (within the next year or two).
In short, the Colts' inside linebacker position is a question mark. Whether you agree or disagree with the decision to let Jerrell Freeman walk in free agency, the reality is that the Colts' current options to replace him don't inspire a ton of confidence.