After reading everyone's articles on what some people missed I narrowed down to what everyone seemed to have missed. That's Bucky acting like a sentry gun for Cap. It happens when Iron Man first appears and says
You seem a little defensive
and when Cap his shown for his response:
Well it's been a long day
In that seen if you look closely you can see Bucky
Can you seen him in the background?
in the trailer you can also see Crossbones, Sharon Carter, and Martin Freeman's character all hidden amongst a crowd or in the background.
I believe that this could be before the fight scene at the end of the trailer. So Bucky is ready to fight for his freedom.
Did you spot Bucky originally?
Why do you think he's there?
Sound off in the comments below