With production rumored to start later this month, Marvel is getting into casting mode forAvengers: Infinity War.Game of ThronesstarPeter Dinklageis reportedly in early talks to star in what is said to be a “key role,” although no details about the character have been given. Marvel would not comment on the casting, and while the character’s identity has not yet been revealed, there is already plenty of speculation about who he may be playing in thisAvengers sequel.

Varietyreports that production is now expected to start at some point this summer, which contradicts another report from last month that claimed Marvel was gearing up for a January 23, 2017production startonAvengers: Infinity War. Filming is expected to take place both in Atlanta, Georgia, at Pinewood Atlanta Studios, and in the U.K. It is also believed that bothAvengers: Infinity WarandAvengers 4will shoot back-to-back.

As forPeter Dinklage’s character, while no details were given by Variety, shortly after the news broke,DeadpoolcreatorRob Liefeldtook to Twitter to reveal his theory, thatPeter Dinklageis playing Pip the Troll, who was originally an antagonist for Adam Warlock. Pip was a Laxidazian alien who became a both physically and psychologically mutated after he became drunk on a mutagenic hallucinogenic ale. He was cast away by his people when he came across Adam Warlock on his travels. Pip was even featured in theInfinity War comics, soRob Liefeld’s theory could certainly be valid, but there is also another theory swirling.

There are also some who speculate thatPeter Dinklagemay be playingMODOK(Mental/Mobile/Mechanized Organism Designed Only for Killing), which also hasn’t been confirmed. It is worth noting, though, thatCaptain America: Civil WarwriterChristopher Markus, who is also writingAvengers: Infinity Warwith his writing partnerStephen McFeely, said in an interview last year that he wants to find a way to bring MODOK into a Marvel movie. While that is far from any confirmation thatPeter Dinklageis playing MODOK, it’s certainly an interesting angle to consider, until we have full confirmation from the studio.

This casting news comes just a few days after another rumor surfaced thatLiv Tylermay be reprising her Betty Ross character from the Phase One movieThe Incredible Hulk, but that hasn’t been confirmed either.Anthony RussoandJoe Russoare directing from a script byChristopher MarkusandStephen McFeely, with Marvel Studios presidentKevin Feigeproducing. There has been talk that the entire Marvel Cinematic Universe will come together to fight Thanos (Josh Brolin), but the studio has yet to confirm a cast list quite yet forAvengers: Infinity War. While best known for his role as Tyrion Lannister in HBO’sGame of Thrones,Peter Dinklageis no stranger to the superhero realm, playing Bolivar Trask in 20th Century Fox’s 2014 movieX-Men: Days of Future Past. While we wait for more onAvengers: Infinity War, take a look atRob Liefeld’s tweet below.