Fortunately for Steve and Bucky, Diarmuid knows some general battle rules, and one of them is that keeping at watch to the front and back are both important. Since he doesn't think he should be at the front, he is more than happy to move to the back.

He is just a little sad he won't be able to see what is going on in front of them very well.

Instead of speaking, he just nods to Steve and then skips to the back of the group. Diarmuid will make sure no one sneaks up on them from behind. He promises!