Here's the thing Keith, it just might be misdirection in a sense. We probably are going after a LB, but we could also be looking at some of the other higher rated players that likely won't be available at 15.
Now if teams traded in front of us to take Cushing and Matthews, this forces to prospects down that wouldn't be there if the LBs weren't taken. For instance, lets suppose that a team in front of us was looking at Jenkins and a team behind us jumped up the other teams spot to grab Cushing or Matthews because they know we will take one of those.
Then as a result, Jenkins is still on the board then we would take Jenkins. It is in essence a ploy for forcing a player down the board who likely wouldn't have been there for our pick. Its a numbers game. Below is an illustrative example:
Taken from ESPN Player Rankings (
http://sports.espn.go.com/nfl/draft)
1 Aaron Curry
2 Michael Crabtree
3 Jason Smith
4 Eugene Monroe
5 Brian Orakpo
6 B.J. Raji
7 Matthew Stafford
8 Mark Sanchez
9 Jeremy Maclin
10 Aaron Maybin
11 Andre Smith
12 Brandon Pettigrew
13 Malcolm Jenkins
14 Knowshon Moreno
15 Tyson Jackson
Now suppose that Cushing and Matthews are both drafted ahead of us ahead of the 13 spot. This would essentially force Jenkins down to us. Then the draft would look like this.
1 Aaron Curry
2 Michael Crabtree
3 Jason Smith
4 Eugene Monroe
5 Brian Orakpo
6 B.J. Raji
7 Matthew Stafford
8 Mark Sanchez
9 Jeremy Maclin
10 Aaron Maybin
11 Andre Smith
12 Brandon Pettigrew
13 Clay Matthews
14.Brian Cushing
15. Malcolm Jenkins
So either way it is almost like playing with house money. They could either take the LB they are high on, or they could force a higher rated player down, but they lose nothing from admitting they are after a LB.
From McNair's comments its clear that they want a LB, but it is also clear that they are not sure they are worth the # 15 pick.
Hope that makes some sort of sense.