After reviewing corner responses, we'll work our way outside-in, addressing the outside and inside linebacker responses to pattern distribution in Cover 2.
Outside Linebacker (weak)
The weak side linebacker who responds to the displaced #2 receiver should be playing a "vertical hook technique". This simply means he is controlling the vertical stem of #2 into the hook zone and will treat this area as a priority. He should be thinking vertical-in-the-seam by #2 on pass key, and defend this throw first. On pass, he must relate to #2 receiver. He will peek to #1 receiver to identify the route concept he should play. As the front will vary depending on formation, we'll focus on just the pass coverage of Cover 2 for the displaced outside linebacker.
#2 Vertical - #1 Outside Vertical
WLB will wall and carry #2 into the seam, peeking to see that #1 is vertical (and outside). With #1 gaining depth outside, the WLB can expect the "all vertical" and / or anticipate a deep drop out / Sail from #2 (and rob from low-shoulder leverage.
#2 Vertical - #1 Inside Vertical
WLB walls and carries #2 vertically into the seam, expecting "all verticals". With an inside/vertical stem of #1, the WLB may anticipate a deep, inside breaking route (dig).
#2 Vertical and Outside - #1 Hitch
WLB should anticipate the "smash" concept and push to the flat. Knowing his corner should be sinking to take the "corner" route, he should be robbing the hitch from inside-and-underneath leverage.
WLB in Cover 2, once the #2 receiver quickly "shoots" to the flat, the WLB should recognize the flat-curl concept. He should expand and wall to the #1 receiver, looking to rob the inside-breaking curl.
Cover 2 Inside Linebackers
In Cover 2, the inside linebackers, both strong and weak, will be keying for run as their primary responsibility. Their gap assignment and key will vary depending on the formation and defensive front they are in. They are reading run-to-pass, and respond accordingly. For the sake of discussion, we will just concentrate on their response after getting a high-hat pass read.
The inside linebackers will match their respective threat based on alignment. This will typically put the SLB or MLB TO or AWAY from the callside based on the strength of formation. An example would be;
MLB will relate to the back (#3) strong or weak, based on back flow.
The SLB/Buck become relates to #2 strong and becomes the vertical seam player him.
Here the defensive front would be adjusted to accommodate the passing (number) threats. The MLB now relates to #3 receiver and the SLB/Buck will relate to the back.
This is a rather simple accommodation as I hesitate to call it an "adjustment". The inside (run) linebackers are simply going to cover down their immediate passing threat. An example of matching the backs with the linebackers is shown below;