According to Movie Pilot on April 6, Marvel Studios president Kevin Feige talked about the reference made about Doctor Stephen Strange in "Captain America: The Winter Soldier". Thoughts about the mystical character being mentioned by Agent Jasper Sitwell were made apparent during a rooftop interrogation scene and one may wonder how this man could be a threat to Hydra.
"Well, 'we' know what it means and where we want to head with it, but we were comfortable with keeping it in there and leaving it in there because there are a few different ways to interpret it. The whole thing, what Sitwell’s saying is, this algorithm is going to predict if you’re going to become a problem for Hydra or not. So you don’t have to just be Tony Stark, actively plotting to save the world. You could be a kid whose SAT scores and whose essays have indicated that you’re going to be a problem one day. So is Stephen Strange the Sorcerer Supreme? Probably not at that point. Is he an unbelievably talented neurosurgeon who’s opinionated and kind of arrogant? Probably. That might put him on the list".
That being said, the theory regarding Doctor Strange's influence before or during the events of "Captain America: The Winter Soldier" are null and void. However, Feige also had an answer as to why Hawkeye had not been present to assist Captain America and the Falcon in their time of need against Hydra or S.H.I.E.L.D. uprising. He seems to imply that some of the comic book characters that had been absent during the Russo brothers film, could be explained or "showcased" as Feige put it in "Avengers 2".
"We will discover, later, the answers to that question. But it really came down to how many players can you have on the field at this time? We really wanted to bring in Falcon, we really wanted to team [Captain America] up with Black Widow, we really wanted Fury to have more of a part than he’s ever had in any of the other movies before. We wanted, ever so briefly, to introduce Sharon Carter. And we had a fun place for Maria Hill to be involved. So we didn’t want to just have, “Hey, I’m Hawkeye! Hey, I’m Iron Man!” We want to avoid the brief cameos of the week....Not every character from every movie is going to be in Age of Ultron, for sure. But Joss [Whedon] is excited and, for the characters you haven’t seen since the first Avengers – like Hawkeye, like Hulk – there’s a reason for that, and that gets showcased quite prominently in Age of Ultron".
It had already been mentioned by Feige in the past that Doctor Strange would be mentioned in the "Captain America" sequel, even during the original draft of the script. Right now it is likely that the Sorcerer Supreme may wind up in phase three.
Joss Whedon's "Avengers Age of Ultron" appears in theaters on May 1, 2015.