According to Jim Irsay's Twitter handle and Bob K of the Star:
Xavier Nixon(OT) and Daniel Adongo(LB) were added to the active roster today. This was done by putting Mario Harvey and Daniel "Boom" Herron on the IR list. I actually like the moves, having Adongo may add some fuel and inspiration for the team that feels stagnant as our benevolent leader, Mr. Wells, has pointed out. Adongo as you know is a former Rugby Star who is taking his chances on making it in the NFL. Hard not to root for the Colt's with Adongo and McNary out there now. Nixon would be security for Linkenbach's current injury. Will the OL ever be healthy? I honestly don't know but the team is trying its best to put an OLine out there that can protect Andrew Luck(though they are failing). I hope the addition of Adongo might add fire to the defense, with McNary another hard worker on there. I know right now with injuries we have lots of new players on the field but the next 4 weeks are critical to put a better team together before the playoffs.
As they say, if(and we should) we make the playoffs it's "any given sunday".