The Sporting Kansas City player, 26, can play in midfield or defence and Latics chief Martinez has revealed the club are close to finalising a deal to bring the Honduras international to the DW next month.
Martinez said: "We're working really hard to try to make it happen and we're looking forward to seeing if we can get that one done successfully.
"There are a few steps: there is the work permit, there are certain aspects we need to fulfil in the paperwork but Roger is a player that we've been following for a long, long time.
"We've seen him enjoying his football in the Olympic Games recently with Honduras, and in the World Cup as well he's been an important part of that group of players with (Wigan defender) Maynor Figueroa. He would be a real asset for us.
"But until January 1 we can't do anymore than wait and make sure we prepare ourselves for the steps we've got ahead to make him a Wigan Athletic player."