NASA's human space flight program plans to within 5 years or so have access to Orion and a launcher for it. Without a Lunar or Martian lander, the targets for Orion missions are limited.
But given that an ISS derived interplanetary habitation module (instead of a lunar lander) is developed next to take care of the 6-8½ month travel time to Mars capture orbit, could the Orion then be used to transport astronauts to the surface of the Martian moons Phobos and Deimos? According to the planned ARM mission, Orion will approach a small asteroid and do an EVA at it. Is it suitable to approach the surface of a Martian moon with the Orion spacecraft? Could it even soft land on its service module in that low surface gravity (0.0006g and 0.0003g)? Orion is designed to manage one EVA and then restore the atmosphere once. But with a mothership habitation module nearby, they might maybe do two EVA's and return to it suited up in an Orion empty of air.