Unlike virtually every other player over 30 (other than Aaron) on the roster, I seriously doubt Hawk will be replaced until he decides to hang them up.
He has never been athletic. He has never made impact plays (sacks, INTs, bit hits). He has never been able to cover back or TEs. He is not a blitzter. He was one of the lowest rated ILBs by PFF last season and is rated just as poorly this season.
Despite these realities, and the fact he has been one of the highest-paid players on the team, there has never, ever been any serious talk of replacing Hawk. If he has not been replaced by now, what would casue him to be replaced next season?
Furthermore, AJ's has 3 important attributes. First, he almost never gets hurt. Second, he knows where he is supposed to be and thus makes a lot of tackles. Many complain that most of those tackles are more than 5 yards past the line of scrimmage and that he almost never makes a tackle for loss, but his availability and tackle numbers cannot be denied.
Hawk's third and, for purposes of this discussion, most important attribute is that TT/the coaches love him. Whereas some players (Woodson, Mike Daniels, Tramon, etc.) have made comments about how changes (in scheme or attitude) were needed on D, AJ has been steadfast in his support of Dom Capers -- and he is the most oft quoted player on the D the past few years.
Hawk's unwavering support of coaches/management no matter how dreadful the D has played the past few years is just the type of attribute that keeps certain players in favor with management. Give AJ credit, I can think of no player who has been paid more money for doing less on the football field.