Black Widow: 10 Major New Details Revealed About The Marvel Movie

Red Guardian is one of the most exciting additions to Black Widow, but he's going to be portrayed quite a bit differently to his comic book counterpart. That version was once married to Natasha Romanoff and was more often than not portrayed as a villain.

Asked what fans can expect from the Marvel Cinematic Universe's Alexei Shostakoff, David Harbour explains that, "He grew up in the Soviet Union during the arms race. He was a soldier. He was chosen for this program as the Americans were developing weapons and, of course, Captain America."

"The Russians were slow to catch up, but they wanted to fight back with their own version of Captain America. He was shot up with a super-strength serum and trained in a certain way. But he didn't become as famous as Captain America – nobody really knows who he is."

Harbour didn't elaborate on why it appears that Alexei is being kept in a Russian Gulag when Black Widow begins, but it wouldn't be overly surprising if the Russians view him as something of a failure...that or the super soldier helped both Natasha and Yelena escape the Red Room!