The Patriots needed a linebacker to replace the injured Jerod Mayo, and while new linebacker Akeem Ayers (acquired for roughly 20 draft slots in the 7th round) isn't going to take Mayo's spot, he will definitely help improve the defense.
The issue with losing Mayo is that he's the signal caller on the defense and he's been the team's most reliable tackler ever since he joined the team. The Patriots needed to try and replace that ability.
Last week against the Jets, the Patriots played a lightweight nickel defense against the Jets power running offense and opted to field just Jamie Collins and Dont'a Hightower on the field for the majority of the game. Hightower was calling the defensive plays in Mayo's stead and it's also clear that he's much more comfortable in the middle of the field than Collins.
The acquisition of Ayers, an outside linebacker in the 4-3, is not to have him play in the middle. It's to allow Hightower to make the full adjustment to the interior. Hightower will now be the thumper in the middle of the field that the Patriots need, while Collins can remain at his more comfortable position on the outside, with Ayers.
Ayers will likely be asked to come off the field on passing downs, but he has quality ability in all three facets of the game: run stuffing, pass rushing, and coverage.
In fact, Ayers gives the Patriots three linebackers with significant experience and ability in all three areas, allowing the Patriots to have more trust in their linebackers. While Mayo was asking to blitz up the middle from time to time, the Patriots opted to rush Hightower off the edge more than a couple times at the start of the season- a feature that's been dormant for the past few weeks. Perhaps Collins or Ayers will get to see time crashing into the backfield over the remaining course of the season.
Yes, Ayers is returning from injury. He'll also be returning to his more natural position than what he's been asked to play with the Titans.
Sam Monson of Pro Football Focus thinks that Ayers' best fit is in a Von Miller-type role of consistently rushing the passer. With Collins, Hightower, and Ayers all capable of generating pressure, you can be certain that the coaching options are all open.