He will be a situational player in a 3-4 defense though as he´s not big and strong enough to play the run in the base.
True.
However, the thing that gets overlooked in these discussions is the fact that within the 65 - 70% of snaps where we run nickel there are a lot of tweener run/pass downs...2nd. and 8, 3rd. and 3, you name it.
Running Jones out there for the bulk of that 65 - 70% (presumably in place of the departing Raji) as a pass rushing specialist presents a problem in stopping the run, particularly when paired with the smallish Daniels. As I'm fond of saying, the opponent is not kind enough to tell us the play in advance.
That leaves the 30% or so of snaps that present obvious passing situations for Jones to play as a specialist. This may well be what we'll see. MM commented in the past week that he'd like to see more defensive variety, with Capers going deeper into his playbook and with more situational substitutions, something that was frustrated last season by the number of injuries according to MM.
I doubt this is the preferred approach theoretically, but rather a concession to the talent on the roster. As recently as the 2011 draft, Capers stated his disinclination toward situational players. This should be no surprise. A purported master of disguises is not likely fond of tipping his intentions by the numbers on the jerseys.
Getting back to Jones, he might fit neatly into a 2014 approach of heavy rotations (see Perry/Neal as well if the latter is re-signed). On the other hand, this is not what you want from 1st. round picks.