Thomas Kretschmann ("King Kong," NBC's "Dracula") has reportedly signed on to play the secondary villain Baron Wolfgang von Strucker in Joss Whedon's "Avengers: Age of Ultron" (and beyond).
In the comics, von Strucker is a Nazi officer working for terrorist organization HYDRA who runs up against both Captain America and Nick Fury.
Hitfix claims that 'Ultron' starts out with von Strucker as the initial threat and he is responsible for bringing Quicksilver and the Scarlet Witch into contact with the Avengers as they start out the film working for the Baron.
However it's a minor role confined mostly to the start, after that James Spader's Ultron becomes the film's major villain.
That said, Kretschmann has reportedly signed on for several films and so it may include a cameo in the upcoming "Captain America: The Winter Soldier".
At present Marvel has no comment on the deal.
Source: The Wrap