Robles signed on loan from Atletico Madrid last week and will remain at the DW Stadium until the end of the season.
Martinez elected to hand his compatriot his debut at Moss Rose and believes Wigan have a "phenonemal" talent on their hands.
"I thought he did really well," the Wigan boss told reporters. "It doesn't get more challenging maybe than making your debut in the FA Cup fourth round away from home.
"I thought he was superb. He didn't get caught by the event. He communicated well and his decision-making and distribution was outstanding.
"I think we saw a couple of flashes of the phenomenal goalkeeper that he is and we are delighted to give him this sort of welcome to the English game."
Robles spent time on loan with Rayo Vallecano last season, starting 13 matches for the La Liga side as they narrowly survived relegation.