Peter Dinklage
Peter Dinklage, winner of the award for best performance by an actor in a supporting role in a series, mini-series or motion picture made for television, for "Game of Thrones," poses backstage at the 69th annual Golden Globe Awards in Beverly Hills, California, January 15, 2012. REUTERS/Lucy Nicholson

Peter Dinklage will be in the cast of “X-Men: Days of Future Past,” director Bryan Singer tweeted Thursday, and fans are speculation about who he will play.

Dinklage had been getting plenty of attention of late as Tyrion Lannister in HBO's “Game of Thrones.”

“X-Men: Days of Future Past” is the follow up to the hit 2011 superhero movie “X-Men: First Class.” In “First Class,” the team was rebooted and set in 1962. Viewers were introduced to Magneto, played by Michael Fassbender, and Charles Xavier, played by James McAvoy, when they were still friends and collaborators and not bitter enemies fighting against one another.

For “X-Men: Days of Future Past,” many of the stars are set to return, including McAvoy, Fassbender, Jennifer Lawrence as Mystique and Nicholas Hoult as Beast. Other “X-Men” actors also set to star in the new movie include Shawn Ashmore as Iceman, Ellen Page as Kitty Pryde, Hugh Jackman as Wolverine, Ian McKellen as the older Magneto, Patrick Stewart as the older Xavier and Anna Paquin as Rogue.

“Days of Future Past” will follow the 1981 comic series arc of the same name. In that storyline, mutants are prisoners in camps and the X-Men failed to prevent the assassination of Sen. Robert Kelly, who runs an anti-mutant campaign, by the Brotherhood of Evil Mutants. The United States is controlled by Sentinels and thanks to time travel, Kitty Pryde warns the present-day team of X-men about the impending doom in the future.

The story will feature both old and new mutants and some believe that Cyclops, played by James Marsden, and Storm, played by Halle Berry, will also return. On Twitter, Singer tweeted “Officially like to welcome #PeterDinklage from #GameOfThrones to #XMEN #DaysofFuturePast Very very excited!”

Without any word on who Dinklage would play, the immediate speculation began. Some believe that Dinklage would play Puck, a non-mutant member of Alpha Flight, Canada’s superhero team. Puck is a dwarf and his small stature makes sense for Dinklage, but in “Days of Future Past” Puck only plays a minor role in the proceedings. Variety says Dinklage would play the main villain, without any sources credited for that information. There is no true main villain, although the Sentinels definitely count, but they are giant robots. Therefore some people believe Dinklage will play the Sentinels' creator, Bolivar Trask. Collider believes Dinklage will play Trask, who will be the voice and personality of the blank Sentinels. “X-Men: Days of Future Past” will begin shooting in April and be released in 2014.