If the season started today, and the Titans rolled out a base 3-4 package, the starting linebackers would be:
LOLB: Akeem Ayers
That cannot be the case when the 2014 season rolls around. So, the question isn't "Will the Titans add a linebacker", it is "Where will they start?".
While I am actually not as down on Fokou and McCarthy as others, I think the Titans need an established presence in the middle of the field. Why not add a veteran player who has been on a playoff team since he came to the NFL: Brandon Spikes.
Spikes is a mean, physical ILB that is built to take on guards and centers, and he has been ranked in the top 10 of PFF's ILB rankings for three of his four years in the NFL. That consistency is something that the Titans will be able to feature in a defense that is still looking for it's "face".
Starting there is a great idea for the Titans, and if they can bring back Bernard Pollard and add someone like Brian Orakpo then that would give Tennessee layers of leadership that it hasn't had since the KVB/Bulluck/Finnegan days.